The opening DJ slot of a night, designed to ease the crowd into the energy that the headliner will deliver.
Definition
A warmup set is the opening DJ slot of a night, played before the peak-time and headline artists. The warmup DJ's job is not to play their biggest tracks — that would steal the headline DJ's thunder — but to ease the early crowd into the room, build up gradually from lower-energy material, and leave the audience and the next DJ in the right place for the energy to climb further. A great warmup set is a craft skill in its own right and is widely respected in the DJ community: many headliners specifically thank their warmup DJs by name, knowing that a good warmup makes their own set significantly easier to land. The opposite — a warmup DJ who plays too aggressively or steals the moment — is one of the cardinal sins of the profession.