Re: Different treatment of \repeat volta in midi

[David Kastrup]

Federico Bruni <address@hidden> writes:

> Il giorno sab 16 lug 2016 alle 16:31, pkarl <address@hidden> ha
> scritto:
>> It would be so nifty if the following snippet produced equivalent
>> output in the midi file to what is produced in the pdf:

[Example using \repeat volta only in one Staff and expecting other
Staves to inherit the repetition when writing \unfoldRepeats in \midi]

>> This would greatly simplify the production of pieces with many
>> parallel staves.

Unless you leave off the Staff where you actually wrote \repeat volta

>> Should this work?  Is it documented that it doesn't work?  Why does
>> it work in the pdf output? Is this a bug of \unfoldRepeats?  There
>> are several warnings about the use of \unfoldRepeats in the Notation
>> Manual, but none of them seem to apply to my snippet.
>
> So in the output of the second score's B instrument there are only two
> bars instead of three, because you did not use \repeat volta in
> musicB.
> What you want is avoiding writing explicitly \repeat volta in each
> parallel staff?
> I remember that I've been warned against this use in this list. And I
> agree that it's better being explicit about \repeat(s) in the input
> code.
>
> I think that this warning may apply to your snippet (replace voice
> with staff)?
>
> """
> When using multiple voices, each of the voices must contain completely
> unfolded repeats for correct MIDI output.
> """
>
> http://lilypond.org/doc/v2.19/Documentation/notation/using-repeats-with-midi.html
>
> Should it be rephrased to "When using polyphony, each of the
> voice/staff..."?

The point is that \repeat as such does not really transfer to other
contexts.  None of \repeat tremolo, \repeat percent, \repeat unfold
affects other staves.  \repeat volta does not affect the printing of
other staff content either but rather makes for unique repeat bar lines
across all staves in the current Timing context.  The material itself is
not repeated using \repeat volta, it only gets somewhat contagious
repeat marks.

-- 
David Kastrup