September chords

September chords are essentially tempered dyadic chords tempered by the september comma, 715/714.

September temperament contains many possibilities for essentially tempered dyadic chords including 20 triads in the 17-odd-limit.

For triads, there are 10 pairs of chords in inverse relationship. The inversely related pairs of chords are:

• 1-14/11-5/3 chord with steps of 14/11-17/13-6/5 and 1-6/5-11/7 chord with steps of 6/5-17/13-14/11;
• 1-12/11-10/7 chord with steps of 12/11-17/13-7/5 and 1-7/5-11/6 chord with steps of 7/5-17/13-12/11;
• 1-14/13-5/3 chord with steps of 14/13-17/11-6/5 and 1-6/5-13/7 chord with steps of 6/5-17/11-14/13;
• 1-13/12-7/5 chord with steps of 13/12-22/17-10/7 and 1-10/7-24/13 chord with steps of 10/7-22/17-13/12;
• 1-13/12-14/11 chord with steps of 13/12-20/17-11/7 and 1-11/7-24/13 chord with steps of 11/7-20/17-13/12;
• 1-12/11-13/7 chord with steps of 12/11-17/10-14/13 and 1-14/13-11/6 chord with steps of 14/13-17/10-12/11;
• 1-11/9-17/13 chord with steps of 11/9-15/14-26/17 and 1-15/14-17/13 chord with steps of 15/14-11/9-26/17;
• 1-13/9-17/11 chord with steps of 13/9-15/14-22/17 and 1-15/14-17/11 chord with steps of 15/14-13/9-22/17;
• 1-14/11-13/9 chord with steps of 14/11-17/15-18/13 and 1-18/13-11/7 chord with steps of 18/13-17/15-14/11;
• 1-18/11-13/7 chord with steps of 18/11-17/15-14/13 and 1-14/13-11/9 chord with steps of 14/13-17/15-18/11.

Equal temperaments with september chords include 31, 41, 46, 72, 87, 94, 103, 111, 121, 140, 183, 224 and 270.