User:UnbihexiumFan/Temperaments

Revision as of 21:38, 10 January 2026 by UnbihexiumFan (talk | contribs) (table & extensions)

A collection of temperaments that I have found that may or may not have yet been discovered. A lot of these are the same as already-known temperaments but with non-octave periods. I am not very good with technical details so even though they are included as info on most temperaments I will not be putting it here.

Stearnsmic 7/4-period temperaments

While searching for temperaments with period 7/4 and generator 3/2 I found that -8 generators (117649/104976) provides a close approximation of 9/8. The difference between these intervals is 118098/117649, which has apparently already been named the stearnsma. Tempering this comma given mapping generators ~7/4 and ~3/2 gives a pretty nice temperament which is essentially the same as no-five stearnsmic with different generators, but gives easier access to the perfect fifth and to septimal thirds.

Interval chain for the 7/4.2.3 temperament tempering the stearnsma:

# Gens Cents[1] Approximate ratios # Gens Cents[1] Approximate ratios
+0 0.00 1/1 -0 968.83 7/4
+1 701.32 3/2 -1 267.51 7/6
+2 433.80 9/7 -2 535.02 49/36
+3 166.29 54/49 -3 802.53 343/216
+4 867.61 81/49 -4 101.22 343/324
+5 600.10 486/343, 343/243 -5 368.73 2401/1944, 81/49
+6 332.59 98/81 -6 636.24 81/56
+7 65.08 28/27 -7 903.75 27/16
+8 766.39 14/9 -8 202.44 9/8
+9 498.88 4/3 -9 469.95 21/16
+10 231.37 8/7 -10 737.46 49/32
+11 932.68 12/7 -11 36.14 49/48

Each half-period can be taken to represent

Bolded ratios are 7/4-reduced harmonics up to 21.

Extensions

The 17th harmonic can be added by equating 17/12 and 24/17 with the half-octave, tempering 442/441 and the 13th harmonic can be added by equating 27/26 and 28/27, tempering 729/728. This provides a comma basis of 442/441, 729/728, and 289/288.

  1. 1.0 1.1 Optimal generator from the Sevish Scale Workshop