Re: midi output questions

[Mats Bengtsson]

One problem of your file is that you have too many staves to
fit into a MIDI file. By default, a new MIDI channel is
used for each Staff, Lyrics or ChordNames context.
Since the maximum number of channels is 16 and channel number 10
is devoted to percussion, there are only 15 available and it
seems that you use a total of 16 channels. When this happens,
LilyPond silently begins to reuse the channels once more, so
channel 1 is used both for the clarinets and the organ.

I'm not sure if this is the reason for the strange sounds, but
you may want to try to either remove the lyric lines from the
MIDI output or to combine the violin parts into a single Staff
context in the MIDI output. Both these options will require a
separate \score{} block for the MIDI version, unless you play some
more advanced tricks with LilyPond. Your Lily version has a bug such
that the lyrics is not included in the MIDI file, I think it has
been corrected in 2.1.x.

At second thought, it should be easy to exclude the lyrics from the
MIDI output without a separate \score{} block, just redifine how
LilyPond handles the Lyrics context in MIDI:

\score{
  ...
  \paper{...}
  \midi{
    ...
    \translator{
      \type "Performer_group_performer"
      \accepts LyricsVoice
      \name "Lyrics"
      \consists "Swallow_performer"
    }
  }
}


   /Mats

Martin Norbäck wrote:
> I've just put up Mozart's Dies Irae (from the Requiem) on
> www.mutopiaproject.org. However, the generated MIDI file sounds a bit
> strange.
>
> There are some strange kind of percussion sounds when I listen to it
> with timidity. Maybe there is a bug in timidity. However, if i remove
> one of the staffs (any staff) the strange sounds disappear.
>
> Can somebody help me with this? I don't really know much about the
> anatomy of MIDI files.
>
> The code is at http://norpan.org/cvs/K626/ (download tarball) or at
> http://www.mutopiaproject.org/cgibin/piece-info.cgi?id=364
>
> I also have another question: I am using tremolo subdivisions in the
> score (mostly because they are that way in the original score). It's
> listed as a bug that they don't carry over into the MIDI output. How
> hard do you think that it would be to fix so that for instance c4:16 is
> output in MIDI as c16 c16 c16 c16?
>
> Any other comments on the score are of course also welcome.
>
> (Yes, I asked about this a long time ago, but I don't know if I got any
> good answers then, so please feel free to answer again.)
>
> Regards,
>
>         Martin