Disc jockey

A disc jockey, more commonly abbreviated as DJ, is a person who plays recorded music for an audience. Types of DJs include radio DJs (who host programs on music radio stations), club DJs (who work at nightclubs or music festivals), mobile DJs (who are hired to work at public and private events such as weddings, parties, or festivals), and turntablists (who use record players, usually turntables, to manipulate sounds on phonograph records). Originally, the "disc" in "disc jockey" referred to shellac and later vinyl records, but nowadays DJ is used as an all-encompassing term to also describe persons who mix music from other recording media such as cassettes, CDs or digital audio files on a CDJ, controller, or even a laptop. DJs may adopt the title "DJ" in front of their real names, adopted pseudonyms, or stage names.

DJs commonly use audio equipment that can play at least two sources of recorded music simultaneously. This enables them to blend tracks together to create transitions between recordings and develop unique mixes of songs. This can involve aligning the beats of the music sources so their rhythms and tempos do not clash when played together and enable a smooth transition from one song to another. DJs often use specialized DJ mixers, small audio mixers with crossfader and cue functions to blend or transition from one song to another. Mixers are also used to pre-listen to sources of recorded music in headphones and adjust upcoming tracks to mix with currently playing music. DJ software can be used with a DJ controller device to mix audio files on a computer instead of a console mixer. DJs may also use a microphone to speak to the audience; effects units such as reverb to create sound effects and electronic musical instruments such as drum machines and synthesizers.

Notable DJs include Skrillex, David Guetta, Porter Robinson, deadmau5, Avicii, Calvin Harris, Martin Garrix, Marshmello, Zedd, Eric Prydz, DJ Snake, R3HAB, Timmy Trumpet, Tiësto, Steve Aoki, Diplo, Nicky Romero, Lost Frequencies, and Daft Punk.

The term "disc jockey" was ostensibly coined by radio gossip commentator Walter Winchell in 1935 to describe the radio work of Martin Block. The phrase first appeared in print in a 1941 Variety magazine. Originally, the word "disc" in "disc jockey" referred to phonograph or gramophone records and was used to describe radio personalities who introduced them on the air.

"DJ" is used as an all-encompassing term to describe someone who mixes recorded music from any source, including vinyl records, cassettes, CDs, or digital audio files. DJs typically perform for a live audience in a nightclub or dance club or a TV, radio broadcast audience, or an online radio audience. DJs also create mixes, remixes, and tracks that are recorded for later sale and distribution. In hip hop music, DJs may create beats, using percussion breaks, basslines, and other musical content sampled from pre-existing records. In hip hop, rappers and MCs use these beats to rap over. Some DJs adopt the title "DJ" as part of their names (e.g., DJ Jazzy Jeff, DJ Qbert, DJ Shadow, and DJ Yoda). Professional DJs often specialize in a specific genre of music, such as techno, house, or hip hop music. DJs typically have extensive knowledge about the music they specialize in. Many DJs are avid music collectors of vintage, rare, or obscure tracks and records.

Club DJs, commonly referred to as DJs in general, play music at musical events, such as parties at music venues or bars, clubs, music festivals, corporate, and private events. Typically, club DJs mix music recordings from two or more sources using different mixing techniques to produce a non-stopping flow of music. Mixing began with hip hop in the 1970s and would subsequently expand to other genres in especially (but not exclusively) dance music. A DJ who mostly plays and mixes one specific music genre is often given the title of that genre; for example, a DJ who plays hip hop music is called a hip hop DJ, a DJ who plays house music is a house DJ, a DJ who plays techno is called a techno DJ, and so on.^{[citation needed]}

The quality of a DJ performance (often called a DJ mix or DJ set) consists of two main features: technical skills, or how well the DJ can operate the equipment and produce smooth transitions between two or more recordings and a playlist; and the ability of a DJ to select the most suitable recordings, also known as "reading the crowd". One key technique used for seamlessly transitioning from one song to another is beatmatching.

DJ Kool Herc, Grandmaster Flash, and Afrika Bambaataa were members of a block party at South Bronx from 1973 onwards. Kool Herc played records such as James Brown's "Give It Up or Turnit a Loose", Jimmy Castor's "It's Just Begun", Booker T. & the M.G.'s' "Melting Pot", Incredible Bongo Band's "Bongo Rock" and "Apache", and UK rock band Babe Ruth's "The Mexican". With Bronx clubs struggling with street gangs, uptown DJs catering to an older disco crowd with different aspirations, and commercial radio also catering to a demographic distinct from teenagers in the Bronx, Herc's parties had a ready-made audience.