Typical contra dance choreography comprises four parts, each 16 counts (8 measures) long. The parts are called A1, A2, B1 and B2. This nomenclature stems from the music: Most contra dance tunes have two parts (A and B), each 8 measures long, and each fitting one part of the dance. The A and B parts are each played twice in a row, hence, A1, A2, B1, B2. While the same music is generally played in, for example, parts A1 and A2, distinct choreography is followed in those parts. Thus, a contra dance is typically 64 counts, and goes with a 32-measure tune.
