Re: Issue 754: \transpose should not affect \transposition (issue 7304044)

[k-ohara5a5a]

On 2013/02/06 11:15:41, dak wrote:
> I don't see
> the point in _not_ inverting the instrumentTransposition sign:
> our documentation gets it wrong, and all regtests are wrong.

I cannot follow the multiple negatives, but I can see some point to
/either/ convention.

1) Storing the pitch written to sound middle C in
instrumentTransposition as in ver2.16 (i.e., the inverse of pitch we use
to describe the transposition, d' for clarinet in B-flat ) means that
all pitches in the stream are /written/ pitches.

The pitch in the event that sets instrumentTranposition would usually be
protected from \transpose, but users would retain the capability to \set
instrumentTransposition  without the protection.  Since all \transpose'd
pitches are written pitches, the effect is consistent.  Some people took
advantage of that consistent behavior
<https://lists.gnu.org/archive/html/lilypond-user/2006-10/msg00074.html>

2) Storing the sounding pitch corresponding to written middle C in the
instrument part (i.e., storing directly the pitch we use to describe the
transposition) is simpler, and most of the documentation thinks LilyPond
works this way already.

https://codereview.appspot.com/7304044/