autoClef ideas (was: Re: [PATCH] autochange.scm: Use averaged chord pitches to determine staff.)

[Mark Polesky]

(creating a new thread to separate the clef stuff from the staff
stuff)

David Kastrup wrote:
> I'll agree that any optionally usable clefs should be specified
> in advance.  A "clef" in this respect may also consist of "8va"
> notations. There are instrument-dependent "thresholds of pain"
> involved: singers' clefs will just not change in midpiece.  I
> don't think that the right hand of a (non-bass) accordion would
> ever change clefs (even though I have a button accordion going
> down to deep A, needing 5 ledger lines,  which is not all that
> untypical).

These are situations when the user would simply not use the auto-
clef function. And when using the function, I think the burden
should be on the user to set the allowable clefs on a case-by-case
basis, not on the program.

> The best strategy probably would be to specify badnesses for
> clef changes (separate for in-bar and between-bar), ledger lines
> (with progressive badness for the vertical arrangement and/or
> badness for ledger lines which actually change the system
> spacing), a large badness for the first clef change, another one
> for a repeat ending with a different clef than it begins...

These ideas sound ambitious to me, but should anyone want to try
implementing them in the future, s/he can consult this post.
- Mark