Re: Pentatonic Diatonic Transposition?

[Tim McNamara]

On Jan 23, 2011, at 6:21 AM, Patrick Schmidt wrote:

> nice work! I just think that the name modal transposition is a little 
> misleading in this case. At first I thought that I could change the mode of a 
> tune with your function e.g. transpose music from c\major to c\minor or 
> something like that.

That's not changing the mode of a song.  That's changing the key.  C major has 
no sharps or flats, C (natural) minor has three flats (C harmonic minor and C 
melodic minor are special cases in terms of notation).  

Modes are within a single key:  Ionian, Dorian, Phyrgian, Lydian, Mixolydian, 
Aeolian, Locrian starting on the 1st through the 7th scale steps with in the 
key, respectively.  

> I just had the idea that it might be useful to add some more scales to the 
> standard LP mode names (\ionian, \dorian ...) such as e.g. \majorPenta, 
> \minorPenta. Maybe there's a way to extend your code and/or the function of 
> the existing \transpose-command to also be able to do real modal 
> transpositions such as e.g.
> 
> <pseudo-code>
> \transpose c\ionian c\locrian \mymusic %or
> \transpose c\majorPenta c\minorPenta \mymusic % etc.
> \transpose c a \pentatonicmusic %or
> </pseudo-code>
> 
> This way users wouldn't have to declare scales and when no modal change is 
> intended  we could just use \transpose.

Changing from C Ionian to C Locrian is a key change, not a modal change.  C 
Locrian is the seventh mode of Db major.

C major pentatonic is a different key than C minor pentatonic, the latter 
having the same key signature as Eb.

Since "modal transposition" necessarily happens within a single key, I am not 
sure that "transposition" is the correct terminology (IMHO modes are largely a 
waste of time for performing musicians but that's a whole 'nother discussion 
that doesn't belong here).