Re: [Denemo-devel] Denemo Hooks

[Nils Gey]

> Hmm, I'm not totally convinced that looking at the key signature would
> be a good overall strategy to decide enhamonic selection. I.e. in the
> key of A minor, how would you select between C# (often in cadences on
> the final with major third - so called 'picardian third') and Db (as
> the minor six above the forth degree in the bass - neapolitan sixt)? I
> could come quite a lot of similar probematic cases. I _do_ agree that
> it would be nice to have some way of controlling enharmonic selection,
> and selection by key signature would be a good default candidate.  For
> my use-cases, being able to manually switch the "tonal center" would
> be fine.


Then please tell a few of the other reasons.
Picardian third is a not a problem. The natural order of notes is the pillar of 
fifths. cis is much nearer than des so its an obvious choice. This also 
reflects musical practise.
The neapolitan sixt of the subdominant is not something needed very often 
compared to the major third of the tonic. 
Its also obvious in A minor if its <e gis b> or <e as b> (Dominant), which is 
Gis because its 5 steps away and As is 7. 

The obvious problem here is 6 steps, which is the tritone interval in both 
directions. Here math can't help but it should be the higher variant (Dis in A 
minor) because Es conflicts with the natural fifths of a minor which is very 
unlikely that anybody wants that regulary.

The last time I thought about this I came across very few cases where there is 
no obvious choice. I would be able to program a system to check the music while 
playing so that you get both C# and Db when you need it, but this requires a 
lot more work and there are more urgent things to do.

Modulations are of course a problem, especially if you follow a more 
traditional way and not change the keysig. 

In Denemos case there are some options:
        -Shifting functions like we have currently. Those could be relative to 
the keysig in the future
        -No-Lilypond Keysigs that can be placed anywhere so that the score has 
more theoretical background and logic in Denemo. 
        -Analysis of the surrounding music in real time. Possible but maybe not 
worth the work yet.


Nils