An ostinato or ground bass variation form of Baroque music in 3/4 time similar to the passacaglia. A chaconne is a set of variations composed upon a continually repeated chord in origin a dance popular in Spain in the early 17th century. it came to signify a form in which there are a series of variations over a short repeated bass or chordal pattern. famous examples of the form are found in Bach's chaconne for unaccompanied violin in his d minor partite or the earlier chacony in g minor by Henry Purcell