Re: duration using variable

[Thomas Morley]

2016-04-27 10:56 GMT+02:00 Gianmaria Lari <address@hidden>:
> I don't know if the following code is well written (suggestions are pretty
> welcome!!) but it works as I like (:)) and let me generate two different
> output according the tag midiOut or screenOut.
>
> \version "2.19.40"
>
> mynote = c
>
> mynoteExp = {\mynote}
> mynoteDouble = {<\mynote' \mynote>}
>
> cC = {\tag #'midiOut \mynoteDouble
>       \tag #'screenOut \mynoteExp }
>
> music =
> {
>   \time 3/4 \clef bass
>   \cC
> }
>
> \score
> {
>   \keepWithTag #'screenOut \music
>   \layout {}
> }
>
> \score
> {
>   \keepWithTag #'midiOut \music
>   \layout {}
>   \midi {}
> }
>
>
> In the attached capture.png you can see the two different output, the first
> when using screenOut and the second using midiOut.
>
> * * *
>
> Now I would like to be able to increase the lenght of the musical expression
> contained in the cC variable.
>
> In the previous example the cC variable contains a quarter note (and a
> quarter bichord) and I would like to change it to an half note. I tried with
> the "changePitch.ly" snippet
> (http://gillesth.free.fr/Lilypond/changePitch/changePitchDoc-sources/changePitch-doc.pdf)
> writing
>
> \changePitch {a2} \cC
>
> but this does not work.
>
> Here it is the whole code (I highlighted the differences compared to the
> previous example)
>
> \version "2.19.40"
> \include "changePitch.ly"
>
> mynote = c
>
> mynoteExp = {\mynote}
> mynoteDouble = {<\mynote' \mynote>}
>
> cC = {\tag #'midiOut \mynoteDouble
>       \tag #'screenOut \mynoteExp }
>
> music =
> {
>   \time 3/4 \clef bass
>   \changePitch {a2} \cC
> }
>
> \score
> {
>   \keepWithTag #'screenOut \music
>   \layout {}
> }
>
> \score
> {
>   \keepWithTag #'midiOut \music
>   \layout {}
>   \midi {}
> }
>
>
> and in the attached file capture2 you can find the output for this second
> scenario.
>
> Consider that:
> - the variable cC will always contain a single note or a single chord
> - I tried using changepitch but any other (possibly simpler) way is welcome
>
> Any suggestion?
> Thank you, g.



Probably:

\version "2.19.40"

%% nb: this is a pitch:
mynote = c

%% this is sequential music, with a NoteEvent in 'elements:
mynoteExp = { \mynote }

%% this is sequential music, with an EventChord in 'elements:
mynoteDouble = { <\mynote' \mynote> }

setNotesDur =
#(define-music-function (mus dur)(ly:music? ly:duration?)
"Set the duration of all 'NoteEvents in `mus' to `dur'"
  (for-each
    (lambda (m)
      (ly:music-set-property! m 'duration dur))
    (extract-named-music mus 'NoteEvent))
  mus)

cC = {\tag #'midiOut { \setNotesDur \mynoteDouble 32 }
      \tag #'screenOut \mynoteExp }

music =
{
  \time 3/4 \clef bass
  \cC
}

\score
{
  \keepWithTag #'screenOut \music
  \layout {}
}

\score
{
  \keepWithTag #'midiOut \music
  \layout {}
  \midi {}
}

Cheers,
  Harm