Re: Lilypond's internal pitch representation and microtonal notation

[Joseph Wakeling]

On 09/21/2010 04:52 PM, Carl Sorensen wrote:
> However, I was wrong in my assumption that something about the key signature
> should determine which of the enharmonic equivalents should be used.
> Instead, it appears that the neighboring notes should govern in tonal music.
> In atonal music, it doesn't matter, except that it does in rapid passages.
> There's virtually no guidance there that I can see for nontonal music.

Stone's guidance about the choice of accidentals is IMO something for
composers to consider rather than Lilypond.  From a Lilypond point of
view, the issue should simply be: the composer can have the accidentals
s/he chooses.

> Transposition of exact quarter tones into appropriate notation is likely to
> remain a *very* tricky problem.

Why do you think so?  If you're transposing in a regular fashion (i.e.
by a certain number of semitones) you just transpose the underlying
notes and preserve the arrows.  If you want to transpose up/down by a
quarter-tone, you just add an up/down-arrow to all the accidentals that
don't already have one; all those that do, you bump them up/down to the
next 'tonal' accidental.

The only thing you have to take into account is that you almost
certainly need to convert double-sharps and flats to naturals of the
staff pitches above and below respectively.  That requirement is one
reason I've been trying to address Lilypond support for chromatic
transposition recently.