A deejay (alternatively spelled DJ) is a reggae or dancehall musician who sings and toasts to an instrumental riddim (rhythm).
Deejays are not to be confused with DJs from other music genres like Hip-Hop, where they select and play music. Dancehall/reggae DJs who select riddims to play are called selectors. Deejays who are more likely to sing are sometimes called singjays.
The term deejay came about as a result of the act of some selectors (as they were called) of the 60's and 70's such as U-Roy or King Stitt toasting to the "version" side of popular records of the time. The "version" came about when the record company produced the 45 record with the song, the flip side of which had the instrumental to the song. This gave the deejays the chance to make up on-the-fly lyrics to the instrumental music. This occurrence gave rise to deejay toasting and the term has been used in that context ever since. Many famous selectors turned deejays include King Stur Gav, Josie Wales, Charlie Chaplin, and Tony Matterhorn.
The top reggae deejay currently is Sean Paul.