Squbemic chords

A squbemic chord is a 13-limit essentially tempered chord which is defined via tempering out the squbema, 729/728.

There are two squbemic tetrads, the temperings of

• 1-9/8-14/9-7/4 with steps of 9/8-18/13-9/8-8/7, and
• 1-9/8-13/9-13/8 with steps of 9/8-9/7-9/8-16/13.

These contain two squbemic triads, the temperings of

• 1-9/8-13/9 with steps 9/8-9/7-18/13,
• 1-9/7-13/9 with steps 9/7-9/8-18/13.

Equal temperaments with squbemic chords include 24, 36, 41, 53, 58, 72, 111, 130, 183, 190, 224, 354, 373, 525, 597, 845, 1028, 1069, 1724, with 1724edo giving the optimal patent val. Squebmic chords belong to a tempering of the 2.9.7.13 subgroup of the 13-limit.