Hexachord (from Gk. hex: ‘six’, chordē: ‘string’)
- Jehoash Hirshberg
A term denoting a series of six notes ascending stepwise through two whole tones, a semitone and two further whole tones, used as a complement to the eight-note diatonic system (including B♭ and B♮) in the teaching of practical music and music theory, and thus in composition (particularly in the later period), from the Middle Ages to the 17th century. The six notes of a hexachord are named after the first syllables of the lines of the hymn ...