HEPTACHORD

Hep″ta‐chord (?), n. [[Gr. επτἅξορδοσ seven-stringed; επτἅ seven + ξορδή chord: cf. F. heptacorde. See Seven, and Chord.]] 1. 1. (Anc. Mus.) (a) A system of seven sounds. (b) A lyre with seven chords.
2. 2. (Anc. Poet.) A composition sung to the sound of seven chords or tones. Moore (Encyc. of Music).