DJ – a person, public public, recorded on sound media musical works with a change. Branches of the profession DJ – sound engineer, etc.
Features of the profession
The DJ mixes compositions using two playback devices (usually record players) and a special mixing console: a DJ mixer. When playing music on both players there should be a continuously adjustable rotation speed (necessary for “smooth” mixing of records with different tempos and rhythms). Also on modern DJ consoles there are samplers (for recording and looping back short sound fragments – loops) and sound effects.
An uninterrupted thematic musical composition is called a mix.
The performance program is called a set. There are sets in which several (two or more) DJs participate together or alternately. Competitive DJ competitions (6-minute performances) are called battles.
The main source material for creating mixes is the recordings of other musicians: as a result, the musical work obtained after the creative processing by the DJ takes on an independent form, called a compilation. In this sense, collage and applique work can be considered a close analogy to DJing in the visual arts. In addition to ready-made gramophone records, a DJ’s arsenal may contain records specially recorded by him (for example, consisting of samples of the same type). Musicians often release special versions of their recordings for DJs.
Records are used as sound carriers, less often magnetic tapes. Audio and MP3 CD players are widely used today. Since the 2010s, a special kind of DJing has become widespread, in which a laptop (laptop) is used with a set of music files and, as a rule, a special DJ controller connected to it, repeating the controls of traditional DJ equipment. There are also combined installations, in which real players are used, but only a special sync signal is recorded on the records, as a result, both techniques that are possible when using real recordings on vinyl and when using a laptop become available (for example, using samples recorded directly during performance ).
As in any direction of art, there are also “stars of the first magnitude” among DJs. Competitions, championships are held annually, lists (tops) of the best DJs in the world, countries, cities are compiled.
In 1979, for the first time in the Soviet space, the trade unions of Kharkov organized courses for disc jockeys, which were read by musicologist Sergei Korotkov 
The well-known music critic Andrei Gorokhov writes in his 2003 book Muzprosvet:
“The highest, last and only goal of a DJ is to encourage people to dance. A good DJ is not at all the one who has good gramophone records, and not the one who knows how to dock them into the long intestine, but the one who is able to control the mood of the dancers, turn on the audience, bring it to a state of ecstasy.  “
DJing art is one of the nominations for the Delphic Games.