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LLL reduced 7-limit kernels of some good ets

🔗genewardsmith@juno.com

11/20/2001 12:19:16 AM

Here's what I got:

10: [49/48, 28/27, 25/24]
12: [64/63, 50/49, 36/35]
15: [126/125, 49/48, 28/27]
19: [126/125, 81/80, 49/48]
22: [225/224, 245/243, 64/63]
27: [126/125, 245/243, 64/63]
31: [225/224, 1728/1715, 81/80]
34: [126/125, 49/48, 6272/6075]
41: [225/224, 4000/3969, 245/243]
46: [1029/1024, 126/125, 245/243]
53: [225/224, 1728/1715, 4000/3969]
58: [1728/1715, 126/125, 2048/2025]
68: [4000/3969, 245/243, 2048/2025]
72: [4375/4374, 225/224, 1029/1024]
99: [4375/4374, 6144/6125, 3136/3125]
171: [4375/4374, 2401/2400, 32805/32768]

This calculation helps to answer the question of which commas we
should list--clearly, 4000/3969 and 2048/2025 are important commas
and belong there.

🔗genewardsmith@juno.com

11/20/2001 12:48:32 AM

--- In tuning-math@y..., genewardsmith@j... wrote:

Some of these temperaments derive from a comma shared by two reduced
bases:

10&15: [49/48, 28/27]
15&34: [49/48, 126/125]
22&27: [64/63, 245/243]
41&53: [225/224, 4000/3969]
41&68: [245/243, 4000/3969]

This might be one place to start.

🔗Paul Erlich <paul@stretch-music.com>

11/20/2001 1:14:12 PM

--- In tuning-math@y..., genewardsmith@j... wrote:
> Here's what I got:
>
> 34: [126/125, 49/48, 6272/6075]

That depends on how you map the 7 in 34.

> 53: [225/224, 1728/1715, 4000/3969]

This is very heartening -- over on the tuning list, I wrote:

"53-tone 7-limit Fokker periodicity block, which approximates the
full 53-tET rather well, without redundancy, and with the smallest
ratios of any of the 62 versions I tried . . . the unison vectors
defining this FPB are 225:224, 1728:1715, and 4000:3969"

> This calculation helps to answer the question of which commas we
> should list--clearly, 4000/3969 and 2048/2025 are important commas
> and belong there.

Why is this so clear. Maybe the ETs with 4000/3969 don't satisfy the
criteria I wish to employ to delimit the project.