4:5:6:7
| Chord information |
har-7 or h7
4:5:6:7, the harmonic seventh chord, is the simplest tetrad in 7-limit harmony. It is often used as a tuning target for the dominant seventh chord in barbershop music (→ Wikipedia: Harmonic seventh chord #Barbershop seventh ), and also for the German augmented sixth chord in septimal meantone.
It is a dyadic chord in the 7-odd-limit, with its most complex interval a 7/5 tritone. It is the octave-reduced version of the first four odd harmonics, 1:3:5:7, or the first eight harmonics, 1::8. It is the fundamental otonal consonance of the 7-odd-limit. The utonal minor version of this chord is 1-6/5-3/2-12/7, sometimes called the subharmonic sixth chord. The harmonic seventh chord can be modified by inflecting the 5/4 down by 25/24 and 7/4 down by 49/48 to get the subharmonic sixth chord.
Rotations around the octave
Related chords
Chords related to this triad (5-limit except where noted):
- 2:3:5:7 - open voicing
- 60:70:84:105 - chord inversion
- 4:5:6:7:9 - adds 9/4 (two octave spanning pentad)
- 12:14:18:21 - substitutes 5/4 with 7/6
