Multiple voices in Lilypond: stem directions, beams, and merged noteheads

Question

With quite a bit of trial and error I figured out a way to write the following bar in Lilypond:

There are four voices, the top voice has upward stems, the two lower voices have downward stems, and the stems of the middle voice (in eighth notes) should be chosen as if there were no other voices. Furthermore, the notes of the middle voice should be beamed per beat.

This is the code:

\new Staff  \relative c' {
  \key b \minor
  \time 3/4
  \clef "treble_8"
  \mergeDifferentlyHeadedOn

<< { \voiceOne d2 d4 } \\
   { \voiceTwo s4 fis,2 } \\
   { \voiceThree \stemNeutral d'8[ b] fis[ b] d[ b] } \\
   { \voiceFour b,2. } >> |
}

I think the code is quite clumsy and I was wondering if there is a more elegant and efficient way to do this. There are still about 50 similar bars to come ...

I would be very curious to know how someone with better Lilypond skills than me would solve such a problem.

Answer 1

If you have 50 similar bars, I would definitely separate each voice into its own variable. The usual way to go about this is making a variable that contains the things that you want to have in each voice, like this:

global = {
    \key b \minor
    \time 3/4
    \mergeDifferentlyHeadedOn
    \mergeDifferentlyDottedOn
    % whatever else you prefer
}

Then you make a variable for each voice, and you include the global variable into the voice like this

one = {
    \global    % this inserts the whole content of the "global" variable
    \voiceOne
    d2 d4 |
    e2 e4 |   % I made up some more notes
    cis2 cis4 |
    % etc.
}

and you make variables for all the other voices in a similar way. Then you combine them together:

\score
{
    \new Staff <<
        \clef "G_8"  % shorter than "treble_8", that's all
        \new Voice \one
        \new Voice \two
        \new Voice \three
        \new Voice \four
    >>
    \layout { }
    \midi { } % only if you want MIDI output
}

In this way, you have four voices, each of them is filled in from one variable (here, they are called \one through \four but you can use more imaginative names). It's a pretty clean solution (you can even split it into multiple files easily) because you can "factor out" the common stuff into the \global variable (again, you can call this variable however you want) and often you can easily make use of things like \repeat unfold etc.