DJs or Disk Jockeys are people who provide entertainment at parties, dances and events by selecting and playing pre-recorded music on a public address system.

Karaoke is an entertainment in which individuals of the audience get on stage to sing along with pre-recorded backing tracks. There is often a Karaoke Jockey (KJ) to handle the equipment and keep the things moving along. This person is often also a DJ by trade.

Ordinarily each aspect of technology in a show is controlled separately. The lights have their own controller, audio has its own controller, and so forth. Show control software allows coordination of the efforts of several different controllers, aiding in synchronization and automation of a show.