[PD] Musical Algorhytmic

Alexandre Quessy listes at sourcelibre.com
Fri Dec 31 07:30:00 CET 2004

Hi Matju, hi list. Happy new year.

I'm not sure of what you are talking about. Unfortunately, I'm not a 
math geek yet. Could you join a simple patch showing a scale and a 
chord in the way you mean ? I am really visual, and not quite a good 
english speaker... Also, for beats, do you send them as a list every 
several beats as in this message : [0 1 3 6{ meaning to play the sounds 
0, 1, 3 and 6 on the beat when it is sent ? A little random in those 
rhythms would help to keep having variety.

If you have the following scale, which is Ionian, how would you then 
assign a priority order in this list ?
0 2 4 5 7 9 11
Then, the following chord would be a Cmaj7...
0 4 7 11
Great, but if I want a Cmaj7(6/9) it would give :
0 2 4 7 9 11
So, it basically means a Ionian scale...
And if I want to play most often the third and the seventh ? It is 

And for licks, should I store them as arrays ? One for the rhythm, the 
other for the melodie...


Oh, by the way, Thanks Hans-Christoph for the patch with the 
data-structure. I had a lot of fun discovering this a little further. 
One day I might release a nice abstraction to build and change data 
structures.  I didn't get your patch to work though. A chance I could 
listen to your MP3. It seems like my Pd couldn't create [debug] and 
[linearpan~]. I also got the following error: ((( 'prepend' class 
incompatibility warning: creating an object without an argument))) I am 
on Mac X, Pd 0.37.4 extended pre-compiled.


> On Wed, 15 Dec 2004, Alexandre Quessy wrote:
>> Forms in musics? (A-B-A-C-A-B-A, variations on a theme and A-B-A, for
>> instance)
> They can be stored as integers in a list, and then applied by using 
> [sel]
> to select various subprograms, or the integer can be used to recall a
> subform. Subforms can obey the same principles.
>> rhytmic patterns,
> Same thing, assign an integer to every drum sound. For more complexity,
> more integers per note can be used, to describe velocity and whatever.
> It's the same as for patterns in melody and such.
>> scales, modes (Do you store only a Ionien and a ascendant melodic
>> minor and derive all the other from them ?)
> I see a scale as a pair of a subset of the 12-note scale together with 
> one
> note of that scale. Following that definition, it can be found that 
> there
> are 24576 of them (I think... well, sum 12!/(i-1)!(12-i)! over i).
> a subset of the 12-note scale may be represented as a 12-bit integer, 
> so
> there are 2**12=4096 of them.
> modes are scales modulo addition of an offset, so there are 
> 24576/12=2048
> of them. They may be represented as 11 bits, each being a toggle for 
> the
> presence of every non-initial note.
> I like to look at those things using modern algebra concepts such as
> group-quotients, group-actions, orbits, and so on.
>> Chords,
> a chord is just a scale with fewer notes than common scales, so they 
> are
> all included in the above. this is considering all notes modulo 12 so 
> it
> doesn't take into account the potential spreading of notes along the
> keyboard...
> I define a subscale as a subset of a scale together with the same 
> starting
> point as the bigger scale (and of course that same starting point must 
> be
> an element of the subset). Therefore, chords C, CM7 are both subscales 
> of
> the full C major scale, and furthermore, some inversions of F, FM7, Am,
> Am7 also are.
> _____________________________________________________________________
> Mathieu Bouchard -=- Montréal QC Canada -=- http://artengine.ca/matju

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