DEEJAYIN: (The study and application of Rap music production, cuttin’, mixin’ and scratchin’ as well as onair radio broadcasting.) Commonly refers to the work of a disc jockey. However, Hip Hop’s disc jockey doesn't just play vinyl records, tapes and compact discs. Hip Hop’s DJ interacts artistically with the performance of a recorded song by cuttin, mixin, and scratchin the song in all of its recorded formats.
Ⅰ Originally presented by two turntables, first designed by Edward P. Casey of the Bronx in 1955, and connected to a mixer with a “cross-fader” first designed by Grandmaster Flash in 1976, Hip Hop’s DJ used the turntable and mixer as instruments that manipulated the playing of vinyl records.
Ⅱ Deejayin, different from “DJ-ing,” includes speaking, even rapping while presenting recorded music.
Caribbean people still use the term deejayin to describe the vocal performances of rhythmic speech over music.
The Gospel of Hip Hop, 2nd Overstanding - The Refinitions, R12 pg 118-119