In jazz music, what is a riff?

A riff in jazz music is a continually repeated musical phrase that serves as a thematic or motif base for improvisation and development within a piece. Riffs typically consist of short, catchy musical ideas, often played by a soloist or a group of instruments, and are utilized to create a sense of cohesion within a performance. This repetition allows performers to build tension, explore variations, and engage in call-and-response dialogues with other musicians, which are essential characteristics of jazz improvisation. The repetitive nature of riffs helps anchor the ensemble while soloists take turns improvising over the established groove, making it a fundamental element in jazz compositions and performances.

Other options may describe different concepts in music, but they do not capture the specific essence of a riff as defined in the context of jazz. A complex chord sequence would relate to harmony rather than a repeated phrase. A type of rhythmic pattern focuses more on rhythm than melody or phrase repetitions, and a variation of a melody implies a reworking of melodic content rather than the specific catchy repetition central to the definition of a riff.