MIDI with ancient notation

[Aleksandr Andreev]

Hello folks,

I've been experimenting with what is supported so far for Kievan
notation, and I've run in to some problems generating MIDI output. I
get the following messages at compile time if I add a \midi block:

warning: cannot find or create new `KievanStaff'
warning: cannot find or create new `KievanVoice'
warning: cannot find or create `Timing' called `'

Looking at performer-init.ly, I see that VaticanaStaff and
VaticanaVoice have their own Context blocks so that makes me think
that KievanStaff and KievanVoice should be implemented similarly.

However, if I typeset some Gregorian chant, as in:

\include "gregorian.ly"
\score {
 \new VaticanaStaff
  <<
    \new VaticanaVoice {
      \[ c'\melisma a \]
    }
  >>
\midi {  }
\layout { }
}

I get no MIDI output -- the resulting MIDI file appears to consist of
a few seconds of rests.

There's probably something I'm not doing right.

Also, I couldn't find anything about MIDI output with ancient music in
the documentation.

Help much appreciated as always!

Aleksandr