microtonal short course

Hey y'all-
Richard Krantz is teaching a 5 week summer short course in
microtonal music here in the physics department to high schoolers,
starting in a couple of weeks. He plans two main activities beyond the
theory: building some theremins (from kits) and learning some Csound.
Experienced Csound users--do you think it is possible in a couple of weeks
to learn enough Csound to demonstrate microtonal tunings, and maybe make
music? If so, what materials, besides the manuals with the Csound
distribution, would you recommend?

John Starrett
http://www-math.cudenver.edu/~jstarret

John
I do not feel experienced enough to say but maybe drop gabriel maldonado a
line but it seems that you can specify pretty quickly 1/2 tones not semis by
say C# = 8.01 C#+ = 8.015 using the cpspch conversion. I think it can be done
if you use a few of the basic toots and show them freq to cpspch
relationships. But a few weeks is cutting it tight
hope this helps!
Now if you want to teach them basic Just Intonation it might be a little
simpler by showing them a basic scale in hz and then having them tweak from
there
ciao
Pat

John Starrett wrote:

> From: John Starrett <jstarret@math.cudenver.edu>
>
> Hey y'all-
> Richard Krantz is teaching a 5 week summer short course in
> microtonal music here in the physics department to high schoolers,
> starting in a couple of weeks. He plans two main activities beyond the
> theory: building some theremins (from kits) and learning some Csound.
> Experienced Csound users--do you think it is possible in a couple of weeks
> to learn enough Csound to demonstrate microtonal tunings, and maybe make
> music? If so, what materials, besides the manuals with the Csound
> distribution, would you recommend?
>
> John Starrett
> http://www-math.cudenver.edu/~jstarret
>
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>From: John Starrett <jstarret@math.cudenver.edu>
>
>Experienced Csound users--do you think it is possible in a couple of weeks
>to learn enough Csound to demonstrate microtonal tunings, and maybe make
>music? If so, what materials, besides the manuals with the Csound
>distribution, would you recommend?
>
Unfortunately, there are no Csound books yet, though the MIT Press book
should be coming out this summer. Other than that, there are some good
Csound tutorials on the web. Check out the Csound front page at:

http://mitpress.mit.edu/e-books/csound/frontpage.html

Traditionally, learning Csound has meant a learning curve not so much
because of the language itself, but because of learning digital synthesis
techniques to implement in Csound. Fortunately, there are now a series of
physical modeling opcodes that can operate like "presets" to give you some
decent sounds while you concentrate on learning tunings or whatever. I saw
Richard Boulanger's presentation at the International Computer Music
Conference last fall in which he used those opcodes to get his students
writing music as quickly as possible.

As for alternate tunings in Csound, there are a lot of possibilities. Plug:
you can wait until the Csound book comes out and see my chapter on
alternate tunings in Csound. Here are a few brief tips.

If you know the cents relative to 12TET, it is easy to specify pitches and
convert them with the cpspch function. In pch notation, the digits in front
of the decimal point refer to the octave, the next two digits to the right
of the decimal point refer to semitones from 00 to 11 (8.12 = 9.00), and
the next two digits the cents. For example, 8.0025 represents a pitch 25
cents (an eighth-tone) above middle C.

For equal temperaments other than 12, there is now the cps2pch opcode,
which takes as its arguments the pitch and the number of pitches per
octave. For example:

ifreq cps2pch 8.07,31

returns the seventh pitch in a 31TET scale above middle C.

If the second argument in cps2pch is negative, then its absolute value
represents the number of a function table with frequency multipliers for
each scale step. For example, here is a function table with factors
representing 1/4-comma meantone:

f 1 0 16 -2 1.000000 1.044906 1.118034 1.196279 1.250000
1.337481 1.397542 1.495349 1.562500 1.671850 1.788854 1.869185

Then in your instrument you would have:

ifreq cps2pch p5,-1 ; p5 is pitch variable from score

You can also use function tables to hold absolute frequencies, which is
useful for representing empirical tunings. For example, here is an mbira
tuning given in Berliner's book (starred notes have been arbitrarily filled
in):

;table time size fn C C#* D Eb E* F F#* G Ab A* Bb B*
f1 0 16 -2 269 287 291 313 336 353 380 392 431 448 469 504

Then in your instrument you would have something like:

instr 1
ioct = int(p5) ; the octave part of the pitch #
ipchclass = 100*frac(p5) ; the pitch class number (0-11)
ipch itable ipchclass,1 ; any fraction left will be truncated
ioctfact pow 2,ioct-8 ; the 8th octave is in the table
ifreq = ipch*ioctfact ; each octave is a power of two
... ; go on to use ifreq as normal

You can use function tables to implement just intonation, but it's usually
easier just to specify the ratios as p-variables from the score. For
example:

;p1 p2 p3 p4 p5 p6 p7
;instr start dur amp num den octave
i4 132.5 0.125 0.9 7 4 10 ; 7/4 ratio

Then in your instrument (i4 in this example):

ioct pow 2,p7-8 ; 8 is the octave of the ref pitch
ifreq = 440 * ioct*p5/p6 ; ref pitch * oct * num/den

Of course 440 could be replaced by any reference. In my pieces, the pitch
reference is a global variable which can be reset by a call to a special
instrument, thus allowing for free modulation.

Best of luck!

Bill

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
^ Bill Alves email: alves@hmc.edu ^
^ Harvey Mudd College URL: http://www2.hmc.edu/~alves/ ^
^ 301 E. Twelfth St. (909)607-4170 (office) ^
^ Claremont CA 91711 USA (909)607-7600 (fax) ^
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Message written at 14 Jun 1999 21:43:37 +0100

Sorry to be late in this but i was away at KlangArt. As well as
cpspch there are the two opcodes cps2pch and cpsxpch which are for nET
scales and (n notes in interval)ET. For Just Intonation it seems
usual to use 3 parameters -- octave, and two ratios. If there is
anything you would like explicitly let me know. Gabriel's code shoudl
work in realtime and it has those opcodes.

You might like to use some of the physical model opcodes as presets as
it woudl allow the students to concentrate on the pitch with
reasonably familiar sounds -- or prepare a set of samples. This may
be a bit far from your interests, but it is what my paper at KlangArt
was about.....

==John ffitch

John Starrett wrote:

> From: John Starrett <jstarret@math.cudenver.edu>
>
> Hey y'all-
> Richard Krantz is teaching a 5 week summer short course in
> microtonal music here in the physics department to high schoolers,
> starting in a couple of weeks. He plans two main activities beyond the
> theory: building some theremins (from kits) and learning some Csound.
> Experienced Csound users--do you think it is possible in a couple of weeks
> to learn enough Csound to demonstrate microtonal tunings, and maybe make
> music? If so, what materials, besides the manuals with the Csound
> distribution, would you recommend?