Hi Jonathan.
Fredobaldi v2.19.0 can do what you are looking for.
Here below is score wizard of frecobaldi generated skeleton code. If you want pinano midi as background, you can move "rehearsalMidi" section after "% Rehearsal MIDI files:" section and add pinano staff after SATB staff. The midi generated whill have what you need.
Immanuel,
Ming
%start
\version "2.19.53"
\header {
title = "highlighted midi output"
}
global = {
\key c \major
\time 4/4
\tempo 4=100
}
soprano = \relative c'' {
\global
% Music follows here.
}
alto = \relative c' {
\global
% Music follows here.
}
tenor = \relative c' {
\global
% Music follows here.
}
bass = \relative c {
\global
% Music follows here.
}
verse = \lyricmode {
% Lyrics follow here.
}
rehearsalMidi = #
(define-music-function
(parser location name midiInstrument lyrics) (string? string? ly:music?)
#{
\unfoldRepeats <<
\new Staff = "soprano" \new Voice = "soprano" { \soprano }
\new Staff = "alto" \new Voice = "alto" { \alto }
\new Staff = "tenor" \new Voice = "tenor" { \tenor }
\new Staff = "bass" \new Voice = "bass" { \bass }
\context Staff = $name {
\set Score.midiMinimumVolume = #0.5
\set Score.midiMaximumVolume = #0.5
\set Score.tempoWholesPerMinute = #(ly:make-moment 100 4)
\set Staff.midiMinimumVolume = #0.8
\set Staff.midiMaximumVolume = #1.0
\set Staff.midiInstrument = $midiInstrument
}
\new Lyrics \with {
alignBelowContext = $name
} \lyricsto $name $lyrics
>>
#})
right = \relative c'' {
\global
% Music follows here.
}
left = \relative c' {
\global
% Music follows here.
}
choirPart = \new ChoirStaff <<
\new Staff \with {
midiInstrument = "choir aahs"
instrumentName = \markup \center-column { "Soprano" "Alto" }
} <<
\new Voice = "soprano" { \voiceOne \soprano }
\new Voice = "alto" { \voiceTwo \alto }
>>
\new Lyrics \with {
\override VerticalAxisGroup #'staff-affinity = #CENTER
} \lyricsto "soprano" \verse
\new Staff \with {
midiInstrument = "choir aahs"
instrumentName = \markup \center-column { "Tenor" "Bass" }
} <<
\clef bass
\new Voice = "tenor" { \voiceOne \tenor }
\new Voice = "bass" { \voiceTwo \bass }
>>
>>
pianoPart = \new PianoStaff \with {
instrumentName = "Piano"
} <<
\new Staff = "right" \with {
midiInstrument = "acoustic grand"
} \right
\new Staff = "left" \with {
midiInstrument = "acoustic grand"
} { \clef bass \left }
>>
\score {
<<
\choirPart
\pianoPart
>>
\layout { }
\midi { }
}
% Rehearsal MIDI files:
\book {
\bookOutputSuffix "soprano"
\score {
\rehearsalMidi "soprano" "soprano sax" \verse
\midi { }
}
}
\book {
\bookOutputSuffix "alto"
\score {
\rehearsalMidi "alto" "soprano sax" \verse
\midi { }
}
}
\book {
\bookOutputSuffix "tenor"
\score {
\rehearsalMidi "tenor" "tenor sax" \verse
\midi { }
}
}
\book {
\bookOutputSuffix "bass"
\score {
\rehearsalMidi "bass" "tenor sax" \verse
\midi { }
}
}