Re: Barcheck failed when MIDI is enabled

[Lukas-Fabian Moser]

Hi Helge,

Am 14.05.21 um 07:43 schrieb Helge Kruse:
> Hello,
>
> I am copying a manuscript that uses volta repeats. The first measure 
> is a upbeat (partial 4).
>
> I get the expected result. I looks like the manuscript. I also want to 
> use the MIDI playback to get an impression how it will sound. 
> Unfortunately I get
>
> PartialRepeat1.ly:65:31: warning: barcheck failed at: 1/2 <d b'>4 <b 
> g'> r8. <d b'>16 |
>
> if the MIDI output is enabled.
>
> Why do I get the warning only for MIDI output and how can I avoid it?
It seems MIDI creation does not deal correctly with the incomplete bars 
in the \alternative's. I didn't have time to check whether this is a 
known issue, but as a workaround, you can let LilyPond unfold the 
repeats for MIDI. For this not to influence the printed version, you 
need two separate \score blocks, so replace your \score { ... } by the 
following:

myScore = \new PianoStaff <<
    \new Staff = "upper" \with {
      midiInstrument = "orchestral harp"
    } \upper
  >>

\score {
  \myScore
  \layout { }
}

\score {
  \unfoldRepeats \myScore
  \midi { }
}

Lukas