13 July 2011

DJ Taxonomy - What is a DJ, what do they do and how do they do it?

DJ Taxonomy - What is a DJ?

A DJ (or disc jockey) is a person who plays various pieces of pre-recorded musical sounds for the listening enjoyment of an audience. The art of DJing has excelled to include the skill of playing, mixing, adding effects and organizing different musical sounds into one expressive form. Some modern DJs even add a bit of their own composition to a musical mix giving it an original flavor. Thus, a DJ can be thought of as a conductor, a composer and a musical programmer.

A typical mixing DJ will play a collection of songs or tracks. The collection is termed a set or mix. Each song will be mixed into the next to give the appearance of a seamless stream of music. The idea is to provide a coherent transition between tracks so that the audience cannot determine when one track ends and the next begins. The music should flow smoothly between tracks and add to or influence the mood of the audience. A DJ is an entertainer. It is their job to invoke energy within an audience and provide musical entertainment for an event. A DJ can also provide visual entertainment as the audience watches the hand motions of the DJ when making a mix. This is a highly under rated component of DJing and may be considered a crucial factor in providing the connection between DJ and audience.

Most DJs have the ability to manipulate their tracks in such a way as they are able create remixes of songs and even create new pieces of music by using elements of their tracks. By adding effects and adjusting various elements of a piece of music, the DJ can alter the sound. When combined with similar actions on various tracks of music, the DJ is able to "glue" tracks together and produce a composition that is a combination of selected sounds from each track. It is important to note that this process could easily be done prior to a performance so that the DJ could just play a pre-recorded set of music. The dynamic factor of a live DJ is that their choice of music is directly affected by the current state of the audience. A pre-recorded set may not suit the mood of the audience and a good DJ will alter their musical choices depending on the audience's reaction and mood. Thus, it is important for the DJ to mix music in a current frame rather than a past frame. Also, part of the excitement of going to see a DJ is to watch how the DJ puts his/her mix together. Watching the motions of the DJ during the performance can be almost as exciting as listening to the music being played.

Turntablist or scratch DJs are especially exciting to watch as their hand movements are fast and complex. They can essentially create new music from very small snippets of pre-recorded sounds. Their records rarely consist of full songs but rather minimalist beats, portions of melodies and vocal samples used to create whole songs. They even produce entirely new sounds with the act of scratching - rubbing a record such that the needle plays back and forth along the groove (not across the grooves). This motion plays a small audio sample back and forth combined with the sound of the needle rubbing against the vinyl. It is one of the keynote sounds of a DJ.

In order to understand the art and process of DJing, one must know the language of a DJ. This section attempts to explain some of the terminology associated with DJing.


This refers to spinning a record backwards for a short and quick spurt. It is used as a special sound effect and can be used to give the peak of a build some more energy or to end songs abruptly.


This occurs when a cross fader breaks after long use. When the cross fader is completely on one side, the opposing channel should not be detected in the output but the broken cross fader will allow some of the opposing channel to "bleed" through. Crossfaders that bleed need to be replaced so that the DJ has control over which channel is played to the audience.


This has several definitions, depending on the context.

1) When referring to "the breaks", it is the part of a song where a drum solo occurs and dancers often pull off their best move. These types of breaks are known to be the best part of the song a culture of hunting down "the breaks" and playing sets consisting solely of "the breaks" now exists.

2) A moment in a musical track where the main beat changes and becomes more subtle. This gives a chance for the dancers to relax a bit and allows for drama to occur as breaks provide a change in the mood of a song. A break will usually occur between downbeats of a track and may span for more than one loop.

3) A genre of electronic music that consists of "broken beats" (i.e. beat patterns where not every note in a 4/4 beat structure consists of a bass drum).

4) To "break a track" refers to being the first DJ to play a song.


A moment in a musical track signified by a strong building sensation, climaxing with an explosion of sound and followed by either a break or a main beat. Builds are usually the most exciting part of a song and are very useful in creating energy within a crowd. The climaxing explosion will occur on a downbeat.

Cross fader

A sliding control device on the mixing board that allows the DJ to transfer the audio output from one source to another in a smooth manner. As the cross fader moves from left to right, the volume of one source decreases while the volume of the other source increases. If the cross fader is completely on one side, only one audio source is played. It is also called a fader for short.


This is the act of finding the correct starting point of a track. With vinyl records, this is done by placing the needle on a certain groove and then moving it back or forth until the needle is above the point that the DJ wants to play. On a CD player, this is done by selecting the track that the DJ wants to play and then scanning through the track (if necessary) to find the correct starting point.


The is the first beat of a loop and is usually signified with an accent or extra burst of sound from and instrument such as a crash symbol or hi hat. If a musical track consists of 16 beat loops, we should hear a downbeat once every 16 beats.


Most modern electronic dance music consists of loops of sound. A loop is a piece of sound that can be played again and again in a coherent sequence. Dance music consists of many types of loops layered on top of each other to create music. One track can contain many loops which may not necessarily be played throughout the entire track. Typically a loop will consist of 16 beats although loops of 4,8,16,32,etc. can also be found.


This is the act of moving the needle back and forth along a groove in a record causing the sound contained within the groove to be played forwards and backwards at various speeds. A DJ will usually have one hand on the record and the other hand on the crossfader located on the mixer. By using the cross fader to cut the volume of the record in and out and moving the record back and forth at various speeds, the DJ can create many unique sounds. The type of sound sample used on the record also affects the sound of the scratch. For more information see the scratching section of this site.

Train Wreck

A train wreck is a term used to explain when two tracks that are playing at the same time have different tempos and/or their beats out of phase. When the audience can hear this, it will sound like incoherent beats occurring at odd times and not making much sense. The term comes from the idea that when your tracks cross, your train will crash, thus a train wreck. This is always a bad thing in a musical mix and is the mark of an amateur DJ.


A person who uses vinyl records and turntables in a manner that involves scratching and cutting the records back and forth to produce new musical output from fractions of the music contained on the records. Turntabilists perform the art of turntabism and know how to perform a variety of scratches and tricks involving playing music from two or more records.


CD Player

The CD (Compact Disc) Player is currently the main method a DJ has of accessing digital audio. In order to qualify as a valid CD player for the purpose of DJing, the unit must provide a pitch control that gives the DJ the ability to speed up or slow down the tempo and pitch of a CD. This is to insure that a DJ can beatmatch two tracks so that they can be mixed properly. Without this feature, it would be impossible to make coherently smooth mixes of tracks.

There are many manufacturers of DJ CD Players and as it is a relatively new method to mix music, an industry standard has yet to arise. Key features in a CD unit consist of:

• Pitch Control
• Instant Starts of Music
• Pitch Bending to adjust the phase of a track
• A Digital Display indicating a track's time remaining and time consumed
• Cue point assignment for creating easy-to-access cue points in a track
• A looping feature to create on-the-fly loops in music
• A scratch pad for "scratching" digital music

As the turntable maintains popularity within DJ circles, the manufactures of CD players are constantly trying to create a CD player that emulates the turntable. Common features found on most turntables have been ported to the CD domain in the hopes of causing a migration towards CD units. Thus we see features such as instant starts, enabling the digital music to be played instantly with the push of a button. This is a one dimensional binary task whose states are started and stopped. Pitch Bending equates to the ability of pushing records forwards to speed them up and applying pressure on a record to slow it down. This is useful when two tracks are running at the same BPM (beats per minute) but are not in phase (see beatmatching for more information). This is a one dimensional continuous task whose options consist of speeding up or slowing down a track. Unlike a record, CD players do no play a track backwards when pitch bending. It is a separate operation from scratching (described below). To pitch bend a track, the DJ would use a special dial on the CD player. Turning the dial in a clockwise motion would speed the music up while turning it in a counter-clockwise motion would slow the music down.

When using vinyl, one can read the grooves in a track to anticipate what will happen in a track. This feature is not maintained in the CD version of this artform and instead, CD can provide accurate information on the time remaining and consumed for each track. This can be useful determining when new tracks need to be mixed in as older ones are close to finishing. DJs, however, are not able to see the upcoming breaks and builds in their tracks and so they must memorize the outline of tracks.

In moving to the digital realm, the CD player can offer some features that a turntable cannot. On-the-fly looping can be performed by setting cue points throughout a track and having the CD unit loop between two cue points to create a seamless beat. On a turntable this would equate to playing a piece of music, lifting the needle and starting it again on the same place. Turntablist DJs create seamless loops with records by using two copies of the same track. When one section of music is played, they cue up the same section on another turntable. When the first section finishes, they cut the output over to the second section and resume play as if the track has looped. This involves two turntables and two copies of the same track. The same effect can be achieved with one CD player, one copy of a CD track and a looping feature. Also, assigning cue points within a track provides the ability to jump to certain sections of a track, effectively creating a remix of the track. Creating cue points within a track is one dimensional binary task that involves simply labeling a time within a track with a cue point. Each unit of time within a track either has a cue point or does not.

In an attempt to provide the one unique feature of a turntable, DJ CD players now come equipped with the ability to "scratch" a CD. On a turntable, the vinyl record can be pushed and pulled back and forth under a needle causing a unique sound known as a scratch. The sound of a scratch is affected by the groove, the needle and the sound sample that is contained within the groove. CD players that offer this feature use a dial, often labelled a scratch pad, where the DJ can create a digital scratch by moving the dial back and forth, much like a record. It differs in two ways. The first is that, the sound produced differs from the analog sound of a vinyl record being scratched. The buffering mechanism involved in a CD scratch must resample the section of track very often and very quickly in order to keep up with the movement of the dial. The sound of the physical needle rubbing along the physical vinyl groove is also not present in the digital version of the effect. The second way in which scratching a CD differs from a vinyl record is the haptic interface associated with each unit. On a CD player, the scratch pad dial is often no bigger than a CD itself. A vinyl record is typically 12 inches providing a much larger surface to handle. One benefit to CD scratching is the lack of skipping that occurs over the turntable method. When scratching a vinyl record, worn needles will often skip out of the groove while a CD player will almost never skip when being scratched. Scratching on either a turntable or a CD player is a one dimensional continuous action where the track either plays forwards or backwards at various speeds.


The turntable has dominated as the most popular physical device used by DJs for controlling pre recorded music. There are many types of turntables but the SL-1200 model produced by Technics has remained the leading type of turntable controller since its creation. It is the industry standard.

Why has the turntable succeeded as the leading controller for music? It has many great advantages over other controllers such as CD players, tape players and 8-tracks.


1. Direct contact with the musical medium (vinyl)
2. Ability to adjust the pitch and tempo of a track
3. Fast access to sections of a track
4. Plays music backwards and forwards
5. Ability to scratch a vinyl record thus producing new sounds
6. Ability to see track information such as length and lulls (breaks) in sound
7. Produces a "warmer" analog sound

The main advantage of a turntable is the direct access to the medium on which the music is maintained. No other musical playback device allows the user to directly access the medium which holds the music. Vinyl records, on the other hand, are large, easily viewable and can be handled easily with a hand. Usually each side of a vinyl record will contain one or two tracks. With such a large surface for a track, the DJ can easily see the grooves in the record. The grooves on the vinyl play an important role in that they show the DJ what will happen in a track. Subtle moments in the music (known as breaks) will be seen as sparsely laid grooves whereas music with lots of frequencies being used will be represented by grooves that are much closer together. By viewing the grooves, the DJ can anticipate changes in the track and act accordingly.

Grooves also play an important part in track selection. When a side of vinyl contains more than one track, the DJ can note the beginning of the sequential tracks by looking for the large dark grooves. If the DJ were to play the third track on a piece of vinyl that contained five tracks on one side, he or she would have to count three grooves in from the beginning of the record and place the needle there. There is a potential for error here as the DJ must correctly place the needle in the proper groove in order to select the correct track. Even after the needle has been placed properly, the DJ must push the record forward a little to find the exact starting point of the track. Each of the dark grooves between each new track consists of a small duration of dead air.

There are other limitations with the turntable. They are summarized as follows.


1. Needles become damaged and need replacing
2. Needles damage vinyl records resulting in lower sound quality
3. Heavy vibrations can cause the needle to skip resulting in an interruption in music
4. Large amounts of vinyl are needed for a set. A large volume of vinyl can become heavy and cumbersome to transport
5. Track selection may be difficult when trying to find the right groove
6. Relatively high cost
7. Limited pitch control
8. Control of pitch and tempo are not separate. Altering one, affects the other

Perhaps the biggest disadvantage with the turntable is the damage which occurs to both the needle and the vinyl records that are used with the turntable. Each time a vinyl record is played, a (diamond-tipped) needle rubs over the surface of the vinyl. Naturally this causes friction which wears the vinyl down over time. Often the needles become worn as well, resulting in an increased amount of skipping as the needle no longer fits snugly into the groove. The combination of these two forms of damage causes a loss of sound quality over time.


The Technics SL-1200 turntable, the industry standard, has six controlling devices that can affect the music. The first three are the primary controls of the turntable as they are used the most often.

1) The record on the turntable itself can be moved back and forth by hand. This provides great control over the speed and direction of the music. By placing a hand on the record as it spins around the platter, the user can speed up or slow down the record, affecting the tempo and pitch of the song. A felt slipmat is placed between the record and platter to maintain the platter’s forward circular motion while the record is held. When the hand is removed, the record resumes its designated speed. A relationship between the movements of the record and the playback of the song is formed from this straightforward mapping. Due to the slipmat, the same relationship does not exist between the turntable platter and the music playback.

Manipulating a record can be useful for positioning the playback point of the music or temporarily adjusting the speed of one track to match another. It is also very useful in the art of scratching a record back and forth to produce new and unique sounds. Since the record can only travel back and forth across the needle, this is a one dimensional continuous task.

Control intimacy is defined by Moore as the compatibility with the performer and his/her instrument when regarding the performer’s psychophysiological capabilities versus the desired sound produced. To clarify, control intimacy provides a satisfying feeling of control from the correct production of a desired sound, via the instrument and the performer’s abilities to use it. Fels explores this concept further and suggests that direct interfaces promote control intimacy. We believe that the direct tangible nature of the turntable provides a high level of control intimacy when used as an instrument.

2) A pitch/speed slider is located on the right side of the unit. It provides a modulation of the platter’s speed within +/-8%. When placed in the middle, the platter should be moving at exactly 33 RPM or 45 RPM, depending on the speed mode; the 33 RPM setting is actually 33 1/3 RPM. When moved toward the front of the unit, the platter will speed up. When moved towards the rear of the unit, the platter will slow down. This is a one dimensional limited range continuous action that spans +/-8% of either 33 RPM or 45 RPM, depending again on the speed mode. If there is no power connected to the platter or the platter has been stopped, this slider has no effect.

3) The needle on the turntable provides random access within a song and temporal position feedback when it is placed in a groove. Placing the needle is a one dimensional limited range linear task.

4) The power switch is a dial on the bottom left of the unit. It has two modes (on and off) and is operated by turning the dial until it clicks, signifying a change in mode. This is a one dimensional binary task. If the power is switched off when a record is spinning, the record does not come to a complete stop. Instead the power for the motor is turned off and the platter containing the record continues to revolve until enough friction causes it to stop. This dial is housed on top of the red strobe light that illuminates the dotted sidewall of the platter. The strobing effect causes the dots on the sidewall to move back and forth, allowing the DJ to determine if the velocity of the turntable platter and the position of the pitch slider are calibrated correctly.

5) A start/stop button is located next to the power dial on the bottom left of the unit. It is used for ‘instant’ starting and stopping of the record. Pressing this button when a record is revolving engages a braking mechanism on the platter, halting the record. Pressing this button when a record is motionless causes the platter to start revolving. The Technics SL-1200 has a starting torque of 1.5kg-cm and a start-up time (from full stop to 33 RPM) of 0.7 seconds [1]. This button is a one-dimensional binary controller with two modes: start and stop.

6) A speed mode switch is located next to the start/stop button and is used for setting the speed of the platter to rotate at either 33 RPM or 45 RPM. This consists of two buttons, each with a light to indicate the mode of the platter. If the light for the 33 RPM mode is illuminated and the 45 RPM button is pressed, the platter switches to 45 RPM. Likewise, if the 33 RPM button is pressed in 45 RPM mode, the platter reduces speed to 33 RPM. If the speed mode button of the current speed is pressed, nothing will happen. Interestingly enough, if the platter is moving at 33 RPM and the 45 RPM speed button is depressed as well as the 33 RPM button, the speed of the platter will speed up to 45 PRM until the 45 RPM button is released and then the platter will resume 33 RPM. This is useful for bending the speed (and pitch) upwards when trying to adjust speeds while beatmatching. If running in 45 RPM mode and both the 33 and 45 RPM buttons are depressed, the effect is to remain in the 45 RPM mode. Thus the modulation can only be achieved upwards from 33 RPM to 45 RPM. This last feature makes the controller a one dimensional binary controller with two modes (33 RPM or 45 RPM) and modulation. We can modulate the speed (and pitch) of a track upwards, based on a mode switch and a proportional time modulation. The more we hold the 45 and 33 RPM buttons down at the same time (when in 33 RPM mode), the longer the modulation of the speed (and pitch).


An audio mixer is a device that takes multiple audio inputs and allows the user to blend them together for a single output. Typically a DJ would have a combination of turntables and CD players feeding into a mixer while the output is sent to an amplifier.

Most standard DJ mixers come with (at least) two channels, a set of three equalizers for each channel and a crossfader to fade smoothly between each channel. Each audio source (eg. a turntable) is connected to one channel on the mixer.

Each channel has a volume slider which controls the amount of volume that the source will output from the mixing board. There is usually also a LED meter to indicate how many decibels a channel is emitting. Controlling the volume of a source is a one dimensional continuous task. Knobs or sliders could be used. Sliders are generally prefers as they can offer more precision in picking the correct volume. They are also usually easier to control as the hand must move up and down instead of twisting around.

The equalizers for a channel usually consist of three knobs that allow the user to adjust the low, middle and high frequencies. Bass tones are generally in the lower frequencies of a track. Vocals and instruments like trumpets and pianos reside in the middle frequency ranges and higher tones such as hi-hats and cymbals are found in the high frequency ranges. Each mixer is different and so there is no standard as to the exact frequency ranges each of these knobs will control. DJs can choose which instruments of a track are accented by adjusting the equalizer knobs. Some mixers allow the DJ to cut those sounds out completely while others provide a range from -32dB to +32dB in sound. Generally if a frequency range is cut back to anything less that -12dB of sound, it is difficult to hear and the DJ can "pseudo-eliminate" it by playing sounds from another source within the same frequency. Adjusting the frequency ranges is a one dimensional continuous task that is usually performed with knobs. Sliders may provide more precision with this but take up much more room than knobs. Also, most mixers only allow access to three preset frequency ranges and do not let the DJ decide where the boundary for the ranges will exist. This also limits the amount of control within a certain frequency range. One low frequency knob can control an entire frequency range which limits precision.

The crossfader is one of the most important aspects of a mixer for DJs who want to perform tricks while mixing. The crossfader allows the DJ to move the output of the mixing board from one channel to another in a manner than incrementally decreases the volume of one source while proportionally increasing the volume of the second source. The crossfader is a continuous control that slides back and forth between two channels. When it is on one side, the output consists of just one source. When it is on the other side, the output consists of the other source. When in the middle, the output is an equal combination of both sources. By snapping the crossfader back and forth with accuracy and speed, a DJ can perform certain tricks with the music such as studders, snapping sounds and quick shifts in music. Most crossfaders wear out in time and start to "bleed". Bleeding is when the crossfader is completely on one side but some of the other source can still be heard "bleeding" through the mixer. This damage is caused by the repetitive snapping of the crossfader on the sides of the control.



Beatmatching is the act of synchronizing two musical beats so that they are in phase as well as in time. When mixing music from one track to another, the transition between tracks can appear seamless if the beats are lined up to be in the same time. This section shall explain the basics behind beatmatching.

Nearly all modern dance music will consist of a series of loops, each containing n beats, where n is a power of 2 and n > 0 (n = 2,4,8,16,32,...). Typically a modern dance track will contain a series of 16 beat loops which is broken down into 4 groups of 4 beats and looks like this:

There will be a extra sound or accent (such as a high hat or crash symbol) that occurs on beat 1. This signifies the beginning of a loop and lets the DJ and listener know what position of the loop they are listening to. We will label this first beat as the downbeat as it will become important when mixing. It is critical for a DJ to know when their music is playing a downbeat and when it is not.

The speed of each track is given in BPMs (beats per minute). This refers to how many of these beats (bars in the above diagram) occur in 1 minute of play. If the above diagram represented 1 minute of music, there would be 17 beats played (the 16 beat loop plus the downbeat of the next loop) and this track would be a 17 BPM track. That is an extremely slow example as most modern dance music can range from as low as 80 BPM to 180 BPM with a few exceptions.

Usually two tracks are involved in a mix. The track that the audience is listening to is called the outgoing track as it will be stopped once a new track is played. The track that is about to be played is called the incoming track. While the outgoing track is playing, the DJ will cue up the incoming track and prepare it for play. When ready, the DJ can mix the two tracks together in a seamless manner so that the audience seems to hear only one constant song. During the mix, the DJ can move the musical output completely to the incoming track and remove the outgoing track from the play device. Then the process starts again and the track that was previously the incoming track is now labelled the outgoing track. A new incoming track is used and the music continues without pause.

To mix two tracks together, two things must happen. The two tracks must have the same BPMs and have their downbeats in phase or lined up in time. When both of these conditions are met, the records are synchronized. Below is an example of two beats that have the same BPM but are not in phase:

When two beats have the same BPM but are not in phase, they will not sound coherent when played with each other as their downbeats will not correspond with respect to time. There are 15 different ways to have two 16 beat loops out of phase as the downbeat of an incoming track can commence on each of the non downbeats of the outgoing track. Thus, we can say that for a loop with n beats, there are n-1 ways to mix it out of phase.

When two beats do not have the exact same BPM, they will eventually go out of phase as the duration between beats of each track will drift further and further apart. Thus, a DJ can get the phases of two tracks synchronized but they will soon unsynchronize themselves as the beat of the incoming record drifts. The following is an example of an incoming beat that has a slower BPM and thus, falls out of phase with the outgoing beat. The slower beat is on the bottom.

When two beats are in phase and have the same BPM, they should be aligned like this:

Let n be a power of 2 and n; 0 (eg. n = 2,4,8,16,32,...).
Let m be a power of 2 and m; 0 (eg. m = 2,4,8,16,32,...).

It is possible to mix any loop with n beats with any other type of loop that has m beats. To do this, one only has to line up the downbeats to occur at the same time. A 4 beat loop will have 4 downbeats in the same time that a 16 beat loop has one downbeat. Thus we can say that any loop consisting of n beats will be mixable with any other loop consisting of m beats as well.


In order to beatmatch, the DJ must use two ears, one listening to the track that the audience is hearing and one listening to the upcoming track. This will require splitting one's attention to accommodate two audio inputs and organizing how things should sound. Most DJs focus on the outgoing track and force the incoming track to follow the beat pattern of the outgoing track. It is common to see a DJ tapping his or her foot to the outgoing track. They are essentially concentrating on the beat of the outgoing track when they do this. Then they cue the incoming track, initializing it to start on a downbeat. When the next downbeat of the outgoing track occurs, they start the incoming track so that the downbeats match. Next they quickly adjust the BPMs of the incoming track so that the beats remain in a constant state of synchronization. This action requires manipulating the speed of the incoming track which requires a device that supports altering the tempo of the track.

Beatmatching involves two procedures. The DJ must start the incoming track at the correct point (a downbeat) and adjust the BPMs accordingly (either faster or slower). Altering the BPMs of a track is a one dimensional continuous task with two directions: faster or slower. It requires great precision as two beats must have the same precise BPMs in order to remain synchronized. A slight variation in BPMs will eventually result in unsynchronized tracks. Once an incoming track is cued to begin on a downbeat, starting the track is optimally a one dimensional binary task (whose modes are playing or stopped). However, most physical devices do not support an instant start and instead take a small amount of time to bring the track to its designated BPMs. Thus the DJ must provide a "push" to the track in order to make sure that its downbeat matches that of the outgoing track. Thus starting a track and putting it in play mode is a one dimensional continuous task that depends on the speed at which the DJ pushes the track.


Scratching a piece of music is one of the main unique musical actions performed by a DJ. The process of scratching is usually done with a turntable and vinyl record although certain CD manufacturers have developed methods of "scratching" or scrubbing digital music on a CD. A DJ that scratches records and performs tricks that involve scratching is called a turntablist or scratch DJ. The good ones perform the art of turntablism.

Scratching a record involves moving the vinyl record back and forth with one hand while moving the crossfader (on the mixer) back and forth with the other. Different sound patterns can be acheived by cutting the sound of the scratch in and out at certain times. The following diagram shows 8 different scratch patterns that can be achieved by moving the record once forward, one backward and cutting the sound on and off with a crossfader.

Diagram by Kjetil Hansen

The sound sample used to create the scratch also has a profound effect on the outcome of the sound. Also, the type of needle and the condition of the vinyl effect the scratch sound as well. There are many different types of scratches that can be performed and more are being developed as this artform grows. The following is a list of some of the more familiar scratches.

Types of Scratches

DJ Q-Bert, one of the world's best turntablists, has outlined at least 25 different scratch patterns in his video "Do it Yourself". New scratch patterns are being created all the time and so this section will outline only some of the main scratch tricks.

The content of this section was sourced from Scratch DJ

Baby Scratch

The simplest of scratches as the baby scratch is performed without using the crossfader. The record is simply moved forwards and backwards (or vice versa) once.

Bubble Scratch

The record is moved back and forth while one of the EQ settings is altered from maximum to minimum, creating a wah-wah pedal sound effect. DJ Noize is credited in finding this technique.

Chirp Scratch

The record is pushed forwards while the sound is faded out with the crossfader. Then the record is pushed backwards while the sound is faded in again. When done quickly a chirp sound is created. This is one of the hardest tricks to perfect but DJ Jazzy Jeff is known for demonstrating this scratch quite well.

Crab Scratch

As the record is being pushed back and forth, the DJ quickly taps the crossfader knob with 2 to 4 different fingers in a sequence starting with the pinkie (when doing 4 taps) ring finger (3 taps) or middle finger (2 taps) while using the thumb as a spring to bounce the fader back out after each tap. The result is much like a very rapid transformer scratch. It is possible to perform a crab in a cyclical motion, producing a “never ending” type of sound.

Flare Scratch

Flares are much like transformer scratches but the DJ starts with the sound on and cut it off rapidly. Each time the DJ bounces the crossfader off the side, it produces a ‘click’ sound. Thus flares are named according to clicks. A one-click flare would involve a sound being played forwards or backwards while the crossfader briefly cuts the sound off in the middle of the playback sequence. This creates two distinct sounds. A two-click flare cuts the sound off twice in the same fashion. This trick was invented by DJ Flare and developed further by DJ Qbert.

Forward and Backward Scratches

Forward and backward scratches are fairly simple scratches. A sound is played either completely forwards or completely backwards. The crossfader is used to cut the sound off when the playback portion has finished. Commonly DJs will perform 2 or more forward scratches in a sequence (thus cutting the sound off when they rewind the audio to the beginning of the sample for the second forward scratch). This scratch is also known as a stab scratch.


As the DJ scratches with one hand, one or more fingers from the second hand are used to apply pressure to the record without stopping its movement. When done properly, the finger bounces slightly off the record and a bassy friction sound is the result.

Orbit Scratch

Technically an orbit is any scratch move performed both forward then backward or backward then forward in a sequence. Generally flares are done using an orbit technique. For example, a one-click forward flare and a one-click backward flare in quick succession (altogether creating 4 distinct sounds), would be a one-click orbit. Likewise, a two-click forward flare and a two-click backward flare in quick succession (6 distinct sounds), would be a two-click orbit. DJ Disk is usually credited as the inventor of this technique.

Scribble Scratch

A scribble scratch is done by tensing the forearm of the record hand, causing the record to jerk back and forth creating the shaky scribble sound.


Strobing is a mixing trick usually done with two copies of the same record. The records are beatmatched so that they are playing the exact same beats at the same time. Then one record’s speed is adjusted to play slightly behind the other. Once setup, the DJ shifts the output (using the crossfader) back and forth, creating a stutter or strobing sound as the beats repeat). DJs Shortkut and Yoshi are credited with this trick.

Tear Scratch

The tear is much like the baby scratch but a short manual pause is inserted halfway through either the forward or backward motion (or both).

Transform Scratch

The transform scratch involves moving the record very slowly forwards and/or backwards, while cutting the sound (via the crossfader) on and off very quickly. The result is a stuttered tremolo effect. DJ Cash Money and Jazzy Jeff are credited with inventing this scratch.

Tweak Scratch

The tweak scratch is performed with the motor of the turntable turned off. You can manipulate the record back and forth in any manner and cut the sound on/off with the crossfader. The result is best achieved with long tone samples and usually provides jerky sounds as your hand hits the record in a different direction. DJ Mix Master Mike is known for performing this scratch.

Zig-Zag Scratch

A zig zag scratch is a move where the DJ uses one hand to push the record, while the other hand briefly taps the record and adjusts the volume fader. If scratching with the right hand on the record the technique would be as follows:

1. the right hand pulls back sound and lets the record go to play the sound forward.

2. the left hand taps the record as it is playing forward, making a quick pause and creating two distinct forward sounds instead of one.

3. then the left hand quickly moves and taps down the volume fader (up or down in a sequence) a small amount

4. repeat the pattern until the volume is all the way down or all the way up.

The effect you get is a 1,2,3 1,2,3 1,2,3... scratch of the sound while the 1,2,3 fades out a little more each time the volume fader is tapped a little lower (the sound can be faded completely out or you can start fading the sound in and out).


Learning to mix music is the main task of a DJ. After much contemplation and practice, we can make the following observations.

Mixing two pieces of music involves five phases: beatmatching, starting the track, introducing the new track, phazing the two tracks and outroing the old track. With each mix of a track, the DJ must follow a set of steps to complete the mix. Here they are:

1. Beatmatching is one of the toughest tasks a new DJ must learn. In order for the musical set to sound coherent, the beats of the outgoing track and the incoming track must be the same. This helps the music flow from one track to another in a natural fashion so that there is little interruption. Conceivably this could be an automated process. If a computer knew the exact BPMs of the outgoing track, it could adjust the BPMS of the incoming track to match. This involves listening to the beats of a track, each signified by a peak in the lower frequencies of music (created by the constant bass drum).

2. Starting a new track is often done incorrectly by amateur DJs. The most common mistake occurs when a DJ successfully gets the incoming track running at the same tempo as the outgoing track (in terms of BPMs) but fails to align the downbeats. It is very important to have the downbeats of both the incoming and outgoing tracks fall on the same time unit. Starting a track is different from introducing it in that the audience may not hear a track being started, whereas they will hear when it is introduced. Thus starting a track can be done 'behind the scenes' prior to introducing the track. Most DJs will start their incoming track and then introduce it into the outgoing track after the first loop has passed. Other DJs will set the tempo and start a new track without hiding the initial start of the track from the audience. When this occurs, starting the track and introducing it are done at the same time. To do this, the DJ must have previously adjusted the BPMs (or be very fast at adjusting them) and must know exactly how much of a push the incoming track may need to be brought up to the correct speed with minimal time. On some turntables, starting a record involves pushing it ahead a little as the motor accelerates up to the proper speed. On CD Players, starting is often more instantaneous and is controlled with the push of a button. It should also be noted that a track does not have to start at the very beginning of the actual song. If the DJ chooses, they can cue up the track at a different point if they want to play a certain portion. Tracks also do not have to be started on a downbeat but they still must have their downbeats lined up. If an incoming track is cued to start on the third beat of a loop, then it should be started on the third beat of the outgoing track's current loop.

3. Introducing a track occurs when the audience first hears the new incoming track in the mix. Prior to this, the DJ could have been cuing up the track to the desired starting point. There are three main ways to introduce a new track. The introduction can be a straight cut, where the music shifts abruptly from one track to another. It could be a half cut, where the incoming track snaps into the mix and plays with at the same volume as the outgoing track. It could also be a fade, where the incoming track fades into the mix. Different DJs like different styles and the type of track being played is also suited to different types of introductions. It should be noted that in modern dance music, most changes within a track occur on a downbeat. Thus the obvious time to introduce a new track (thus changing the musical mix) is on a downbeat. Mixes often sound more coherent if the audience hears the new track introduced on a downbeat. If done properly, they may interpret this as only a change in the current track without realizing that a new track is being played.

4. Phazing two tracks is the heart of musical mixing. This occurs when two tracks are being played simultaneously as if they were one track. To phaze two records and make it sound coherent, the melodies of each track must make harmonious sense. A common rule of thumb is to never mix two vocals portions with each other as it causes two distinct streams in which the audience must follow and does not allow for unification within the music. Beats must remain in line so slight variations in BPMs must be adjusted to make sure that the phazing portion is going smoothly. Expert DJs will be able to phaze two tracks for their entire length. Amateur DJs will only be able to phaze for a short while and will opt to fade one track out quickly to insure that a there is no incoherent beatmatching occurring in the mix (resulting in a "train wreck"). While phazing, the DJ can adjust the equalizers for each track thus accenting various instruments within each track. The DJ can also cut back and forth between the two tracks to create a new beat or melody. Generally, phazing is considered the funnest part of DJing because this is where the DJ gets to use their creativity and talent to produce new pieces of music and to accent the tracks. There are many tricks on how to use different parts of a track to produce different effects such as building up the energy in a song or mellowing it down by removing the drums. New breakbeats can be created by cutting the different drum loops in each song back and forth.

5. Outroing a track involves moving the mix completely over to the previous incoming track and removing the outgoing track from the setup. This can be done by fading the old track out, cutting it off or waiting for it to finish. Some DJs' can perform tricks on the outro as well, such as stopping the track abruptly causing as screeching sound. Another popular trick when outroing records is to cut the power to turntable so that the record slowly comes to a halt. Backspins, spinning the record backwards in a quick spurt, can be effective for outroing too.

To illustrate these concepts, let's look at a mixing scenario. We will use the traditional turntable as our input device. First we play a record. Let's call it record1 and let it consist of 13 32-beat loops. That means that one loop consists of 32 beats and there are 13 of them in the song. Each 32-beat loop is broken down into 8 sub sections (displayed below in different colours) and we can count each beat as follows:

ONE two three four
TWO two three four
THREE two three four
FOUR two three four
FIVE two three four
SIX two three four
SEVEN two three four
EIGHT two three four

Record1 is a standard dance song that consists of an intro, a middle and an end (or outro). The intro is rather boring and consists of a bass drum that occurs on each beat (32 bass drums per loop) and a bass guitar that plays a tune. It plays for 2 loops. The outro is even more boring as it has the same bass drum on each beat and a hi-hat on the off beat (occuring exactly in the middle of two successive beats. The outro is 1 loop long. On the downbeat (labeled ONE) of the entire track there is a crash symbol sound. Thus we hear the crash symbol once every 32 beats. The middle is 10 loops long and contains the "meat" of the track. Here we hear guitars, pianos and trumpets. As with all dance music, each new instrument begins and ceases to play on a downbeat. The song is 120 BPMs and there are a total of 416 (= 13 * 32) beats in the song.

Record2 is another standard dance song that has an intro, a middle and an outro. It has 18 loops and in this case, each loop is 16 beats long. The intro and outro are both 2 loops long and consist of the bass drum (occuring on each beat) and some congas and bongos that play between and on beats. The middle of the this track consists of a energitic female vocalist singing in full stream. Record2 is 122 BPMs and there are 288 (= 18 * 16) beats in the song.

We have heard both tracks before and know when the middle part of the record1 ends. It is at this time that we want to start playing record2 so that the 32 beats of outro on record1 will line up with the 2 sets of 16 beats on the intro of record2. The plan is to make the middle portion of record2 begin just as record1 finishes. Thus we want to start record2 on the downbeat (labelled ONE) of the last loop in record1.

We begin with record1 starting on its first loop and playing through. We select record2 and place it on the turntable. We can cue it up by listening to record2 in the left side of our headphones. Our right ear is listening to the speakers playing toward the audience while our left ear is listening into our headphones. We cue up record2 so that the very first beat is directly under our needle. On the 33rd beat of record1 (the downbeat of the second loop), we release record2 and set it in playing mode. We are not actually introducing it now, but rather setting up its BPMs to match record1's BPMs. As the beats of the two records play, we can tell that record2's bass drum is occuring a little before record1's bass drum. We apply a slight amount of pressure on record2 to slow it down with one hand and adjust the pitch controller so that the rotation of the record is slower with the other hand. The more we slow down the pitch controller, the less pressure we have to apply to record2. While continuing to listen we find that record2's bass drum is now occuring just after the bass drum of record1. We have slowed record2 down too much and need to adjust the pitch controller while pushing the record ahead just a little to compenstate for the difference. After 16 beats have gone by from record1, we have decided that we now have record2 at the correct BPM setting (120 BPMs). We can start record2 off from the beginning again to test and make sure. We cue it up to start on its first beat and set it in play mode at the beginning of the third loop in record1 (the 65th beat). The two records ride nicely together and the beats seem to be in synchronization. Let's introduce a little of record2 to the audience. We snap the cross fader into the middle position on the 81st beat of record1 while record2 is on its 17th beat (the beginning of the second loop for record2). This is the middle of the 3rd loop on count FIVE for record1. Note that we did not introduce the track on a downbeat. But we are still following the rules of 4/4 time because we are introducing a new element in the music at a multiple of 4. Essentially, we have cut the 32 beat loop in record1 in half by introducing a new element in the middle of a loop. Now our mix consists of a piano, a trumpet a guitar and some conga and bongo drums (along with the bass drum). We let this mix ride for 16 beats and then fade it back to record1 so as not to let the melodies of the middle section in record2 interfer with an opposing melody that is occuring in record1.

Now the audience has had a taste of the second record and may think that the new conga and bongo drums are part of record1. We can inject them a few more times into the mix but recueing record2 and mixing the first 2 loops into record1. Finally, when the middle section of record1 is about to end, we can start record2 off on the first downbeat of the next loop in record1. This time we will let record2 ride all the way through without fading it out. Our mix now consists of a bass drum, some conga and bongos and a hi-hat. After 2 loops (and 32 beats) in record2, record1 comes to and end and record2's middle section begins. The audience is used to the conga and bongo drums by now and so there is coherence in the mix. Upon record1's finish, the exciting vocal of record2 begins and the audience does not miss record1 as they are now enticed by the new elements brought into the mix by record2. We can now remove record1 from the turntable and select a new track to mix into our set.

Mixing is the heart of DJing and is one of the funnest parts of being a DJ. It should be noted that most musical changes in tracks occur on downbeats and so when mixing, a DJ should follow the same method and also inflict changes on a downbeat. This makes the mix consistent with the format of the music and again, leads to coherence. On the other hand, new and creative mehtods for mixing music can be found by not following some of these rules and trying new and unique ways of intertwining tracks. As this is a relativly new form of creating music, there are no hard set rules, only suggestions based on what has worked well in the past.

The Challenge

What are the challenges of DJing? What are the toughest parts of being a DJ? To answer this, we should break the problem up into two categories, the problems of the amatuer DJ and the problems of the expert DJ.

The Amateur DJ

DJs who are just starting out have lots of challenges to overcome. Once they have had enough practice, most of these challenges will cease to be a problem. In the meantime, some of the toughest things for a beginning DJ are:

• Matching the tempos of two tracks. The DJ will listen to an outgoing track and try to get the speed of the incoming track to play at the same tempo. Most often, the DJ will not be able to determine whether the incoming track needs to be sped up or slowed down. They become confused as to which beat is coming from which track and cannot tell whether speeding up or slowing down a track will solve the problem.

• Aligning two seperate beats so that they are in phase. This is caused mainly by a misunderstanding of musical timing. Many amateur DJs feel that matching the tempos of two tracks is sufficient for mixing but they fail to realize that each track will progress and change on a downbeat. To make the mix sound more natural, one should follow the rules of musical timing and cause the new portions of the incoming track to occur on the downbeats of the outgoing track. This problem can also be caused when the DJ loses count of the beats and does not know which beat (in the set) they are hearing. They may incorrectly assume that they are coming up to a downbeat but guess incorrectly. This can be caused by not pay attention to the outgoing track for a small period of time, thus causing the DJ to lose the beat timing of the outgoing track. Often a DJs attention to the outgoing track will be diverted if they are concentrating on finding the correct incoming track or even the right portion of the incoming track. Also, if the DJ becomes engaged in other activites, such as conversations with friends, they may lose track of which beat is occurring in the outgoing track.

The Expert DJ

Many people feel that pro DJs are at ease when mixing music. There are, however, a few problems that even they encounter while performing a set:

• Track selection is always a concern. After speaking with many top DJs, it was found that the biggest problem for most DJs is deciding what track to play next. This is a problem that involves understanding the mood and anticipations of a room full of people (the audience). The DJ must know what type of music their audience wants to hear. Will the mix become faster, or slower, harder or softer, happier or darker, vocals or not? Often musical selection is affected by the age group of the audience, the decor of the venue, the time of day, the type of event and the mood of the DJ.

• Mixing melodies is often a problem. When the melodies of two tracks are played on top of each other, sometimes they do not create a harmony and can sound quite unnatural. Some professional DJs organize their music collection by using key signatures. Then they know when one key will conflict with another and they will not attempt to mix two opposing tracks. Others will practice mixing their tracks before performing in front of an audience. Practice sessions will help a DJ learn which tracks sound nice with each other and which ones do not sound coherent. Using the equalizers can help in reducing dis-harmonious melodies. Also, there is a famous unwritten rule in DJing - never mix vocals on top of each other. This almost always creates two melodies that do not sound harmonious together. It also makes the audience concentrate on two sets of lyrics, a task that involves mental effort and takes away from the feeling of becoming "lost" in the music.

Many thanks to Timothy Wisdom