Disco Jockey-Someone who plays songs at a party

A record is also known as a disc. Some who plays and changes records at a party is a DJ. ( Disc Jockey) Compact Discs and computers have changed being a DJ. DJs create their own blends of beats and songs. A jockey is most commonly someone who rides a horse in a race, jockey can also mean "To direct or maneuver by cleverness or skill" So you can see how this applies to someone who scratches records and blends beats.

DISCO jockey ( disc jockey)