Re: smart transpose

[Mats Bengtsson]

>               Hello,
>       I use lily a lot for transposing my score.
>       Transposing is one of the borest tging in music (and I play a Bb instrum
> ent,
> so I know the problem).
>       With lily the \transpose commande work fine but I often have B#, E#, and
> 
> other boring note.
>       I tied to use smart-transpose has describe in the smart-transpose.ly 
> file
> but the result is not what I whant.
>       Is it possible (before 1.4, it would be great, but I understand that we 
> must
> decided to stop at one moment :o) to have a command \smart-transpose, working
> like \transpose (and maybe \smart-transpose instead of \transpose, who like
> B# ? or Cx ?)
>       If it's not possible to include this feature yet, I send one of my .ly 
> file
> I'd like to transpose, if anyone can explain me how it work... I understand
> that I would normaly give me a .dvi with the same musique one transpose and
> the other not, but it's not what append... In fact, of course, I only want
> the transpose one :o)
>       Thank's,
>               nemo.

I'm not exactly sure how you want to transpose your example.
Both copies of your music is tranposed in the example, 
\transpose cs' \music raises one semitone and 
\apply #(lambda (x) (smart-transpose x (make-pitch 0 5 1)))
raises 10 semitones (c to a sharp, and so on). 
As a first step to understand the two tranposition mechanisms,
I'd suggest that you make the same transposition both times:

\transpose cs' \music
\apply #(lambda (x) (smart-transpose x (make-pitch 0 0 1)))
       \music

Then, you will notice that the smart-transpose is not very smart,
since it doesn't transpose the key signatures. If you set the
key signature manually to the transposed key, I guess the result
is more or less what you want.

I think it would be better to use the builtin transpose function
and implement a Scheme function 'simplify' that makes the desired
enharmonic changes, something like 
\apply #simplify \transpose cs' \music
I don't have the time right now to implement it, but some 
Scheme hacker on the list should be able to do it.
This function might be useful also in other situations where you 
don't want to transpose but the composer wrote something unreadable. 

On the other hand, I find it confusing to see an 'f' instead of 
an e sharp if the melodic function of the note is e sharp, but
that's individual and probably also dependent on the instrument.


I notice that you still use whole notes in 2/4, are you sure that
you don't want c2 (or possibly c1*1/2) instead of c1, to get rid
of the extra bar lines.
Also, you may want to use ties for tied-over notes, 
for example df8 ~ df4 instead of df8( )df4

  /Mats