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re: Porcupine notation

🔗Carl Lumma <carl@lumma.org>

2/26/2002 3:09:41 PM

>I take Porcupine temperament to be an approximately 163c generator
>with primes 3,5,7,11 mapping to -3,-5,6,-4 generators, (11-limit sans
>9's). I'd notate the 7 note MOS as
>
>A Bv C^ D Ev F^ G
>
>v and ^ represent both the syntonic comma and the undecimal diesis and
>correspond to 1 step of either 15 or 22-tET, and 2-steps of 37-tET.
>Feel free to substitute your favourite comma symbols, everyone else
>does :-)

Is this equivalent to my suggestion?

> E#
> / \ / \ / / / .
> C#--G#--D#--A#^-E#^-
> / \ / \ / \ / \ / \ ,
> A---E---B---F#^-C#^-G#^
> / \ / \ / \ / \ / \ /
>F---C---G---D---A^--E^
>
>So in tunings with positive fifths, the # raises two steps
>and the ^ raises 1, and with normal fifths the # works as
>normal and you ignore the ^. The progression is then:
>
>15 (E, G#min, C#, E#=E^, A^, C#^, F#^, B, E)

I've been looking at Porky as a fifth generator... maybe
Gene can tell us where the fifth and the 163-cent generators
diverge (as far as series of ets).

Don't forget about 29, Dave!

-Carl

🔗Carl Lumma <carl@lumma.org>

2/26/2002 3:12:26 PM

>The progression is then:
>
>15 (E, G#min, C#, E#=E^, A^, C#^, F#^, B, E)
>
>Right, except it actually starts on Eb. (C-E is a minor third in
>porcupine notation, so porcupine E corresponds to traditional Eb.)

I was just ignoring absolute pitch in that example. My notation, is
not the same as your original proposal (C-E is a major third), I'm
sure you realize?

>>12 (E, G#min, C#, E#=F, Bb, D, G, C, F), or
>> (E, G#min, C#, E#, A#, Cx, Fx, B#, E#), right?
>>
>>Does this make sense?
>
>Yes, that's one way of looking at it. I've used similar notations except
>with the D a fifth below A rather than the one above G. But if you're going
>to start notating commas, I think it's almost easier to use the Pythagorean
>fifths and write Eb, G-, C-, E--=Eb+, Ab+, C, F, Bb, Eb.
>
>. --- G#
>. / \
>. -- E---B
>. / \ / \
>. - C---G---D---A---E
>. \ / \ / \ / \ / \
>. start-> Eb--Bb--F---C---G
>. \ / \ / \ / \
>. + Db--Ab--Eb--Bb

So what commas do +/- and #/b control here?

>Porcupine notation is to the porcupine tunings what Graham Breed's decimal
>notation is for the MIRACLE temperament. The notes A-G are equally spaced,
>based on the generator of the porcupine scale (2 steps of 15-ET, 3 of
>22-ET, or 5 of 37-ET). Two steps up is a minor third, three steps a perfect
>fourth, and five steps a minor sixth. A step above G is notated as Ab, and
>the cycle keeps going, adding more and more flats. Similarly, a step below
>A is G#, and more sharps are added as you go down the scale.
>
>. G---D---A E#--B# Fx--Cx
>. \ / \ \ / \
>. Eb--Bb F---C G#--D#--A# Ex--Bx
>. / \ \ / \ \ / \
>. Gb--Db--Ab E---B F#--C# Gx--Dx--Ax
>. \ / \ \ / \ \ / \
>. Ebb-Bbb Fb--Cb G---D---A E#--B# Fx--Cx
>. \ / \ \ / \ \ / \
>. Gbb-Dbb-Abb Eb--Bb F---C G#--D#--A#
>. \ / \ \ / \ \ / \
>. Fbb-Cbb Gb--Db--Ab E---B F#--C#

Hmm. Intrestin'.

-C.

🔗dkeenanuqnetau <d.keenan@uq.net.au>

2/26/2002 10:34:29 PM

--- In tuning@y..., Carl Lumma <carl@l...> wrote:
> >I take Porcupine temperament to be an approximately 163c generator
> >with primes 3,5,7,11 mapping to -3,-5,6,-4 generators, (11-limit
sans
> >9's). I'd notate the 7 note MOS as
> >
> >A Bv C^ D Ev F^ G
> >
> >v and ^ represent both the syntonic comma and the undecimal diesis
and
> >correspond to 1 step of either 15 or 22-tET, and 2-steps of 37-tET.
> >Feel free to substitute your favourite comma symbols, everyone else
> >does :-)
>
> Is this equivalent to my suggestion?
>
> > E#
> > / \ / \ / / / .
> > C#--G#--D#--A#^-E#^-
> > / \ / \ / \ / \ / \ ,
> > A---E---B---F#^-C#^-G#^
> > / \ / \ / \ / \ / \ /
> >F---C---G---D---A^--E^

Not if the above is your suggestion. D:A and B:F# are P5s in mine (not
D:A^ and B:F#^). I really don't like these Ben Johnston style
notations.

> Don't forget about 29, Dave!

I consider it a very poor porcupine temperament. You'd be using
second-best ratios of 7.

🔗Carl Lumma <carl@lumma.org>

3/3/2002 12:44:58 PM

Dave Keenan wrote...
>>>I take Porcupine temperament to be an approximately 163c generator
>>>with primes 3,5,7,11 mapping to -3,-5,6,-4 generators, (11-limit
>>>sans 9's). I'd notate the 7 note MOS as
>>>
>>>A Bv C^ D Ev F^ G
>>>
>>>v and ^ represent both the syntonic comma and the undecimal diesis
>>>and correspond to 1 step of either 15 or 22-tET, and 2-steps of
>>>37-tET.

Aha! What does the lattice look like?

>> Don't forget about 29, Dave!
>
>I consider it a very poor porcupine temperament. You'd be using
>second-best ratios of 7.

The 2nd-best in 29-equal. But Gene and all this linear temperament
stuff now shows that thinking about equal temperaments as fundamental
musical entities is a mistake! They are just convenient ways to
package linear temperaments.

-Carl

🔗dkeenanuqnetau <d.keenan@uq.net.au>

3/3/2002 6:36:54 PM

--- In tuning@y..., Carl Lumma <carl@l...> wrote:
> Dave Keenan wrote...
> >>>I take Porcupine temperament to be an approximately 163c
generator
> >>>with primes 3,5,7,11 mapping to -3,-5,6,-4 generators, (11-limit
> >>>sans 9's). I'd notate the 7 note MOS as
> >>>
> >>>A Bv C^ D Ev F^ G
> >>>
> >>>v and ^ represent both the syntonic comma and the undecimal
diesis
> >>>and correspond to 1 step of either 15 or 22-tET, and 2-steps of
> >>>37-tET.
>
> Aha! What does the lattice look like?

Which lattice? Here's the 5-limit lattice for the 7 note MOS.

Ev--Bv
\ / \
G---D---A
\ / \
F^--C^

There's only one subminor seventh (4:7), that's A:G. There are three
super fourths (8:11), G:C^, F^:Bv and Ev:A.

> >> Don't forget about 29, Dave!
> >
> >I consider it a very poor porcupine temperament. You'd be using
> >second-best ratios of 7.
>
> The 2nd-best in 29-equal. But Gene and all this linear temperament
> stuff now shows that thinking about equal temperaments as
fundamental
> musical entities is a mistake! They are just convenient ways to
> package linear temperaments.

OK. So 4/29 oct is far from an optimal Porcupine generator if you want
to approximate some JI.

🔗David C Keenan <d.keenan@uq.net.au>

3/5/2002 11:56:07 PM

To see the following properly formatted on Yahoo's dopey web interface you'll need to choose Message Index, then Expand Messages.

Here are two periods of Porcupine-7.

Ev--Bv
\ / \
G---D---A
\ / \
F^--C^
\
Ev--Bv
\ / \
G---D---A
\ / \
F^--C^

Here are two periods of Porcupine-15.

Dv--Av--Ev--Bv--F#v
\ / \ / \ / \
C---G---D---A---E
\ / \ / \ / \
Bb^--F^--C^--G^--D^
\ / \ / \ / \ / \
Dv--Av--Ev--Bv--F#v
\ / \ / \ / \
C---G---D---A---E
\ / \ / \ / \
Bb^--F^--C^--G^--D^

Here's an 11-limit-sans-9s sliderule for Porcupine-15

D^ E F#v G^ A Bv C^ D Ev F^ G Av Bb^ C Dv
|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
5--11-3--------1-----------------7

-- Dave Keenan
Brisbane, Australia
http://dkeenan.com

🔗Carl Lumma <carl@lumma.org>

3/6/2002 10:14:34 AM

>To see the following properly formatted on Yahoo's dopey web interface
>you'll need to choose Message Index, then Expand Messages.

I'm back on e-mail, now, and it's the best thing I've ever done. :)

>Here are two periods of Porcupine-7.
>
>Ev--Bv
> \ / \
> G---D---A
> \ / \
> F^--C^
> \
> Ev--Bv
> \ / \
> G---D---A
> \ / \
> F^--C^
>
>Here are two periods of Porcupine-15.
>
>Dv--Av--Ev--Bv--F#v
> \ / \ / \ / \
> C---G---D---A---E
> \ / \ / \ / \
> Bb^--F^--C^--G^--D^
> \ / \ / \ / \ / \
> Dv--Av--Ev--Bv--F#v
> \ / \ / \ / \
> C---G---D---A---E
> \ / \ / \ / \
> Bb^--F^--C^--G^--D^
>
>
>Here's an 11-limit-sans-9s sliderule for Porcupine-15
>
>D^ E F#v G^ A Bv C^ D Ev F^ G Av Bb^ C Dv
>|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
>5--11-3--------1-----------------7

Great, Dave!

-C.