Aequale
An equale or aequale (from Latin: voces aequales, equal voices or parts) is a musical idiom. It is a piece for equal voices or instruments.[1][2] In the 18th century the equale became established as a generic term for short, chordal pieces for trombone choirs, usually quartets or trios. The instruments were not necessarily equal in pitch, but formed a closed consort.[3]