Backbeat - Upbeat

Upbeat

1. An unaccented beat or beats that occur before the first beat of the following measure. In other words, this is an impulse in a measured rhythm that immediately precedes, and hence anticipates, the downbeat. It can be the last beat in a bar where that bar precedes a new bar of music.

2. An anticipatory note or succession of notes occurring before the first barline of a piece, sometimes referred to as an ‘upbeat figure’, section or phrase. An alternative expression is "anacrusis" (from Greek. ana: "up towards" and krousis: "to strike"; Fr. anacrouse). This term was borrowed from poetry where it refers to one or more unstressed extrametrical syllables at the beginning of a line.

3. The upward stroke made by a conductor to indicate the beat that leads into a new measure.