vamp
A repeated chord progression or riff used as an introduction, interlude, or background for improvisation.
In Depth
A vamp is a short musical pattern — usually 1-4 bars — that repeats indefinitely until a cue signals the next section. Vamps are used as introductions (the band vamps until the singer enters), as backgrounds for solos, and as transitions between sections.
In jazz and popular music, the instruction vamp till ready tells the band to keep repeating the pattern until the soloist or singer gives the signal to move on. Many famous songs are built on vamps: Herbie Hancock's Chameleon is essentially a single vamp, and much of funk and hip-hop is vamp-based. The term may derive from the word vamping, meaning to improvise or patch together.
Herbie Hancock's Head Hunters album (1973) is essentially 40 minutes of vamps — repeating grooves that the band plays over and improvises on. It became the first jazz album to go platinum.