Harmonic seventh chord

"Tempered harmonic seventh" chord on C with the 7th at 950 cents above C. Playⓘ See: three-quarter flat.
Just harmonic seventh chord on C with the 7th 968.826 cents above C, a septimal quarter tone lower than B♭. Play justⓘ
Dominant seventh chord on C, C7, with the 7th 1000 cents above C. See flat. Playⓘ

The harmonic seventh chord is a major triad plus the harmonic seventh interval (ratio of 7:4, about 968.826 cents[1]). This interval is somewhat narrower (about 48.77 cents flatter, a septimal quarter tone) and is "sweeter in quality" than an "ordinary"[2] minor seventh, which has a just intonation ratio of 9:5[3] (1017.596 cents), or an equal-temperament ratio of 1000 cents (25⁄6:1).

  1. ^ Bosanquet, Robert Holford Macdowall (1876). An elementary treatise on musical intervals and temperament, pp. 41-42. Diapason Press; Houten, The Netherlands. ISBN 90-70907-12-7.
  2. ^ "On Certain Novel Aspects of Harmony", p.119. Eustace J. Breakspeare. Proceedings of the Musical Association, 13th Sess., (1886–1887), pp. 113–131. Published by: Oxford University Press on behalf of the Royal Musical Association.
  3. ^ "The Heritage of Greece in Music", p.89. Wilfrid Perrett. Proceedings of the Musical Association, 58th Sess., (1931–1932), pp. 85–103. Published by: Oxford University Press on behalf of the Royal Musical Association.