Passacaglia

A continuous variation form built over a repeating bass melody (ostinato), typically in triple metre. Closely related to the chaconne but traditionally distinguished by its melodic rather than purely harmonic ostinato.

The passacaglia developed alongside the chaconne in 17th-century Spain and Italy. In keyboard and organ music it was cultivated by Buxtehude, Pachelbel, and Handel, and reached its greatest expression in Bach's Passacaglia and Fugue in C minor BWV 582. The form was revived in the 20th century by composers including Brahms, Britten, and Shostakovich.