Bar

One measure of music, bounded by vertical barlines, containing the number of beats stated by the time signature.

Bars exist so that musicians can find their place quickly in a long piece and so that repeating patterns can be counted rather than described. Rhythm players think in bars constantly, since chord progressions are usually counted in multiples of two, four or eight bars, and a twelve-bar blues is named for exactly this unit. Counting bars rather than beats is also what makes playing with a band possible without rehearsal.

Example: A twelve-bar blues is a form whose chord progression repeats every twelve bars.

Bar

See also