Ground;  Ground bass

A short melodic phrase (normally four to eight measures) that is repeated over and over again as a bass line, with varying music for the upper parts.  The resulting composition is also called a "ground."   The ground is a characteristic form of the Baroque period and was cultivated especially in England, frequently with improvisation of the upper parts.

The ground belongs to the general category of continuous variations.  In particular, passacaglia and chaconne can be considered grounds.

(see also Ostinato)