Re: A must-see for anybody on this list

[Joseph Rushton Wakeling]

On 02/12/2013 02:50 PM, David Kastrup wrote:
> Joseph Rushton Wakeling <address@hidden> writes:
> > What you actually want to see in a given passage is something like,
> >
> > {
> >    \set Staff.transposition = #'chromatic
> >    c'4 bf' gs' e'    % any transposition applied to this passage
> >                      % will be chromatic
> >    \set Staff.transposition = #'tonal
> >    c' d' e' f'       % whereas this will be treated tonally
> > }
>
> That does not make all that much sense: transposition works at a time
> when contexts are not live or active, so context properties are not
> useful generally.  They _could_ be used for manipulating the manner in
> which _quoted_ music is getting transposed: this happens on-the-fly
> during context interpretation.

Well, we can discuss the right way to do it in terms of Lilypond's notation, but 
the fact remains that musically what you want to be able to say is,

{
   %% If you transpose the following, please do so in a chromatic way
   c'4 bf' gs' e'    % any transposition applied to this passage
                     % will be chromatic
   %% If you transpose the following, please do so in a tonal way
   c' d' e' f'       % whereas this will be treated tonally
}


A function that wraps, like naturalizeMusic, doesn't cut it, because if I do 
something like,

  \naturalizeMusic {
      % a chromatic passage
      % a tonal passage
      % a chromatic passage
  }

then the naturalization will affect both the chromatic _and_ tonal passages, and 
that's undesirable.