Re: changes.tely: deal with \transposition and instrumentTransposition changes (issue 7404046)

[dak]

On 2013/02/27 07:40:59, Keith wrote:
> On 2013/02/27 05:58:58, Keith wrote:

> > (and @code{\whateverItWasCalled f'} is available

> Oops.  It was \oldTransposition  but it was not put into LilyPond.

Since the sign of instrumentTransposition has been inverted, it would
require serious trickery or a separate music event type to implement
\oldTransposition with the previous semantics.  Getting the previous
semantics for instrument definitions seems even worse.

> On the one hand, any score that used \transposition p  in music that
goes
> through transpose will change its behavior.

Yes.  I think the most likely candidates would be
\transpose c' bes { \transposition c' ...
where "\transposition c'" is used in the meaning "I don't care what you
do with \transpose, the following is concert pitch".

It might make some sense to complain about this special case and/or the
pattern
\transpose [letters, spaces, octaves]*{[space]\transposition
in convert-ly rules.

> On the other hand, I /think/ that the only cases where the old
behavior was
> useful would have one \transposition at the start of the section of
music, so
> transforming to the new LilyPond is simple---rather, relatively simple
in the
> world of writing for transposing instruments.

> Back to the first hand, search/replace to use \oldTransposition  is
easier to
> explain to the impatient, than how to write for transposing
instruments.

The problem I have with supporting \oldTransposition behavior in the
standard code is that we won't ever get rid it again.  We still have an
"old-relative" option to revert to LilyPond 1.8 behavior for \relative,
and the associated code paths.  Probably nobody has a clue what this
actually does, or whether it actually still does what it was intended to
do once.

https://codereview.appspot.com/7404046/