A chaconne (also ciaccona, chacona) is a musical form developed during the baroque era. It employs a repeated bass-line (called the ground bass) or either a repeated harmonic progression, which is used as a device for melodic variation, ornamentation, etc. Historically, composers have used the terms 'chaconne' and 'passacaglia' indiscriminately and interchangeably, and attempts by music historians to define each of these forms have arrived at contradictory results.