A-team
A-Team is a 2.9.21 temperament generated by a tempered 21/16 with a size ranging from 5\13 (461.54¢) to 7\18 (466.67¢), or to about 470¢ if you don't care about tempering out 81/80. Three 21/16's are equated to one 9/8, which means that the latrizo comma (1029/1024) is tempered out. It's natural to consider A-Team a 2.9.21.5 temperament by also equating two 9/8's with one 5/4, tempering out 81/80. The generator generates 5-, 8-, and 13-note MOSes, most notably the 8-note "oneirotonic" MOS; see also 13edo#Modes_and_Harmony_in_the_Oneirotonic_Scale.
13edo, 18edo, and 31edo all support A-Team; 31edo gives the optimal patent val for the 2.9.21.5 subgroup interpretation, with the 12\31 generator only 0.13 cents sharper than the POTE generator of 464.3865 cents.
Its name is a pun on the 18 notes in its proper scale, which is a 13L 5s MOS.
Generator chain
| Generators | Cents | Ratios*
notation |
Generators | 2/1 inverse | Ratios
notation |
|---|---|---|---|---|---|
| 0 | 0.00 | 1/1 | 0 | 1200.00 | 2/1 |
| 1 | 464.39 | 21/16 | -1 | 735.61 | 32/21 |
| 2 | 928.77 | 12/7 | -2 | 271.23 | 7/6 |
| 3 | 193.16 | 9/8, 10/9 | -3 | 1006.84 | 16/9, 9/5 |
| 4 | 657.55 | 16/11 | -4 | 542.45 | 11/8 |
| 5 | 1121.93 | 40/21 | -5 | 78.07 | 21/20 |
| 6 | 386.32 | 5/4 | -6 | 813.68 | 8/5 |
| 7 | 850.71 | 18/11 | -7 | 349.2945 | 11/9 |
2.9.21.5.11 ratio interpretations