Proposal: modes about tonal HOT 3 CLOSED

Hi @edellaq

Sorry for the delay. Circular shift of pitch class sets are implemented in pcset package:

tonal.pcset.modes('c d e f g a b');

However, sometimes it has problems properly naming the notes. Take a look to https://github.com/danigb/tonal/blob/c7bf9572e5ce42511a6a64ff830fd23e2f96c92b/packages/core/pcset/test/pcset.test.js#L25

Also, you can get the name of the modes using the key module:

tonal.key.names();

See https://github.com/danigb/tonal/blob/c7bf9572e5ce42511a6a64ff830fd23e2f96c92b/packages/extensions/key/test/key.test.js#L34

I'm curious about the scale transformation and parallel modes. Can you write a little bit more about it?

I hope it helps.

from tonal.

Hi @danigb, my concept is:
having a major scale note array, simply returning the array starting form the n-th note, by shifting it circularly, returns the new modals scale...
So that e.g. a c major scale [c,d,e,f,g,a,b], shifted by 3 steps gives a F lydian scale [f,g,a,b,c,d,e]
without altering any note.
A bit more complicated is when you want a parallel mode, having the same root note.
starting from a C major scale [c,d,e,f,g,a,b], if you want a C lydian [c,d,e,f#,g,a,b] you'll have to raise only the 4th grade (f to f#)
So I was thinking to a function using circular shifting to obtain new a modal scale starting from any current one, and another function using some kind of "transformation matrix" for scales, that alters only the degrees needed to obtain the new parallel mode (= having the same root)
Each returned object would be a regular "scale" object, to be used seamlessly in any computation...

So for example you can have by shifting:
Gmixolydian=Cmajor.mode(5)
and then by 'parallelizing':
Gdorian=Gmixolydian('toDorian')
that simply flattens the 3rd degree of the mixolydian scale...
etc..

from tonal.

I think this is implemented in tonal-key. Please feel free to reopen if not.

from tonal.