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Nonradical fifths

🔗Gene Ward Smith <gwsmith@svpal.org>

4/22/2005 12:10:00 PM

The theoretical intervals derived for tempering are nearly always
algebraic numbers, though there are exceptions--examples being Golden
Meantone and Lucy Tuning, where the fifth is a transcendental number.
An algebraic number is called a radical if it is of the form p^q,
where p and q are rational numbers. Much of the time the algebraic
numbers used are of this form, but sometimes they are not. Some
meantone fifths which are exceptions are:

Holden 4f^4-3f^3-10 697.656 cents, almost exactly 1/5 comma

Keller f^4+2f-8 697.278 cents, almost exactly 5/23 comma

Smith 3f^3+4f-16 695.978 cents, almost exactly 5/18 comma

Wilson f^4-2f-2 695.630 cents, almost exactly 5/17 comma

This might be a good subject for the Encyclopedia of Tuning.

🔗monz <monz@tonalsoft.com>

4/22/2005 2:36:59 PM

hi Gene,

what's the "f"?

i'm too busy to write new webpages now ... if you could
write up something more detailed about this, i'll make
a page of it, to be uploaded when the new version of
the Encyclopedia is ready.

-monz

--- In tuning@yahoogroups.com, "Gene Ward Smith" <gwsmith@s...> wrote:
>
> The theoretical intervals derived for tempering are nearly always
> algebraic numbers, though there are exceptions--examples being
Golden
> Meantone and Lucy Tuning, where the fifth is a transcendental
number.
> An algebraic number is called a radical if it is of the form p^q,
> where p and q are rational numbers. Much of the time the algebraic
> numbers used are of this form, but sometimes they are not. Some
> meantone fifths which are exceptions are:
>
> Holden 4f^4-3f^3-10 697.656 cents, almost exactly 1/5 comma
>
> Keller f^4+2f-8 697.278 cents, almost exactly 5/23 comma
>
> Smith 3f^3+4f-16 695.978 cents, almost exactly 5/18 comma
>
> Wilson f^4-2f-2 695.630 cents, almost exactly 5/17 comma
>
> This might be a good subject for the Encyclopedia of Tuning.