Ground bass

Ground bass: Late Renaissance and Baroque

Ground bass or basso ostinato (obstinate bass) is a type of variation form in which a bass line, or harmonic pattern (see Chaconne; also common in Elizabethan England as Grounde) is repeated as the basis of a piece underneath variations. Aaron Copland describes basso ostinato as "... the easiest to recognize" of the variation forms wherein, "... a long phrase—either an accompanimental figure or an actual melody—is repeated over and over again in the bass part, while the upper parts proceed normally [with variation]". However, he cautions, "it might more properly be termed a musical device than a musical form."