Often instrumental blues used ‘riffs,’ also – single rhythmic phrases repeated over and over, as a background to the melody, or as the melody itself. Jazz today uses riffs. It also uses ‘breaks,’ which come from the blues. At the end of a phrase of melody or words, there is a little pause, during which one or more instruments break away from the melody and make up some fill-in music (pg 20).
This is why I get angry when I watch dancers ‘hit’ all breaks by standing still. If a musician or band leaves you some space, you should fill it. Not every time, but often enough to show you’re listening. This is also why we teach our beginners about break steps in their first or first class. First you set up the rhythm, then you break it. You aren’t just dead weight in this song; you have to bring something to the party, because you are part of the band. When someone calls, you respond.