A disc jockey (abbreviated D.J., DJ or deejay) is a person who mixes recorded music for an audience; in a club event or rave, this is an audience of dancers. Originally, "disc" (uncommonly spelled "disque" in French or commonly "disk" in American English)referred to phonograph records, not the later compact discs. Today, the term includes all forms of music playback, no matter which medium is used.
The title "DJ" is also commonly used by DJs in front of their real names or adopted pseudonyms as a title to denote their profession and the music they play.
There are several types of disc jockey. Radio DJs or radio personalities introduce and play music that is broadcast on AM, FM, digital or internet radio stations. Club DJs select and play music in bars, nightclubs or discothèques, or at parties or raves, or even in stadiums. Mobile DJs travel with portable sound systems and play recorded music at a variety of events. Some mobile DJs also serve as the master of ceremonies (MC) directing the attention of attendees, and maintaining a room-wide focus on what is included in the event's agenda. There are also many competitions that specialise in mixing, scratching or other kinds of techniques.
Other types of DJ use musical performance techniques that allow them to be categorized as performing musicians, depending on the situation. Hip hop DJs not only select and play music using multiple turntables to back up one or more MCs/rappers, but they also perform turntable scratching to create percussive sounds, and are also often songwriters and/or music producers who use turntablism and sampling to create backing instrumentals for new tracks.
In reggae, the DJ (deejay) is a vocalist who raps, "toasts", or chats over pre-recorded rhythm tracks while the individual who helps the DJ by selecting tracks to be played is called the selector.
Many electronica artists and producers who also work as DJs often perform music by combining turntablism with keyboards or live electronics. Electronica, hip-hop or reggae DJs also often collaborate and play live music with bands and musicians from several musical genres (rock, heavy metal, jazz or even classical music), using turntables and electronics as musical instruments. According to a 2012 study, there are approximately 1¼ million professional disc jockeys in the world.
The tunes a dj picks to play and in which they mix them comes together to define a DJ style. The DJ style can and should be pliable, depending on what club that is being played in and what kind of music is expected of the dj.
Club DJ equipment may consist of:
Sound recordings in a DJ's preferred medium (for example, vinyl records, CDs, computer media files, etc.)
A combination of two devices (or only one, if playback is digital) to play sound recordings, for alternating back and forth to create a continuous playback of music (for example, record players, Compact Disc players, computer media players such as an MP3 player, etc.)
A multiple sequencer which can mix MIDI tracks with Digital Audio
A sound system for amplification or broadcasting of the recordings (for example, portable audio system, public address system) or a radio broadcasting system
A DJ mixer, which is an (usually 2- or 4-channel) audio mixer usually equipped with a crossfader used to smoothly go from one song to another, using two or more playback devices Headphones, or earphones used to listen to one recording while the other recording is being played to the audience, or to listen to both recordings simultaneously; and
Optionally, a microphone, so that the DJ can introduce songs and speak to the audiences.
Other equipment could or can be added to the basic DJ setup (above), providing unique sound manipulations. Such devices include, but are not limited to:
Electronic effects units such as delay, reverb, octave, equalizer, chorus, etc. Some club DJs use a subharmonic synthesizer effect which either doubles low frequencies with energy added an octave lower or synthesizes harmonics such that the impression of a very low bass sound is added to the mix.
A computerized performance system, which can be used with vinyl emulation software to manipulate digital files on the computer in real time.
Multi-stylus headshells, which allow a DJ to play different grooves of the same record at the same time.
Special DJ digital controller hardware that can manipulate digital files on a PC or laptop.Samplers, sequencers, electronic musical keyboards (synthesizers), or drum machines.
A Midi controller used to trigger different aspects of DJ software, such as Serato Scratch Live, VirtualDJ and Traktor.
Equipment and technique
Several techniques are used by DJs as a means to better mix and blend recorded music. These techniques primarily include the cueing, equalization and audio mixing of two or more sound sources. The complexity and frequency of special techniques depends largely on the setting in which a DJ is working. Radio DJs are less likely to focus on music-mixing procedures than club DJs, who rely on a smooth transition between songs using a range of techniques.
Club DJ turntable techniques include beatmatching, phrasing and slip-cueing to preserve energy on a dancefloor. Turntablism embodies the art of cutting, beat juggling, scratching, needle drops, phase shifting, back spinning and more to perform the transitions and overdubs of samples in a more creative manner (although turntablism is often considered a use of the turntable as a musical instrument rather than a tool for blending recorded music). Professional DJs may use harmonic mixing to choose songs that are in compatible musical keys.
Recent advances in technology in both DJ hardware and software can provide assisted or automatic completion of some traditional DJ techniques and skills. Examples include phrasing and beatmatching, which can be partially or completely automated by utilizing DJ software that performs automatic synchronization of sound recordings, a feature commonly labelled "sync". Most DJ mixers now include a beat-counter which analyzes the tempo of an incoming sound source and displays its tempo in beats per minute (BPM), which may assist with beatmatching analog sound sources.
In the past, being a DJ has largely been a self-taught craft but with the complexities of new technologies and the convergence with music production methods, there are a growing number of schools and organizations that offer instruction on the techniques.
