Lilypond: define MIDI output file name

Question

I am trying to make Lilypond create a MIDI output file whose name corresponds song title, but I didn't succeed so far. Maybe someone can help?

From the Lilypond notation reference (https://lilypond.org/doc/v2.20/Documentation/notation/creating-output-file-metadata):

For each type of output file, only the \header definitions of blocks that define separate files of that type, and blocks higher in the block hierarchy, will be consulted. Therefore, [...] for MIDI files, all headers above or at the \score level are used.

Here is my code:

\music = { \relative c'4 d e f}

\bookpart {
  \header {
    title = "my Title"
  }
  \score {
    \music
    \midi { }
  }
}

I expected to get a midi file named my Title.midi, but instead, I get a file whose name is the name of the lilypond file (so if myLilypondFile.ly, then myLilypondFile.midi).

From the same source:

The title variable sets also the sequence name for MIDI. The midititle variable can be used to set the sequence name independently of the value used for typeset output.

So I tried adding midititle to my existing header:

\header {
    title = "my Title"
    midititle = "my midi Title"
}

but it did not change anything. It seems the midititle variable isn't even known (I use Frescobaldi and it does not syntax highlight that variable).

My lilypond file is version 2.20.0 and I have also installed GNU lilypond 2.20.0.

Answer 1

You're on the right track for sheet music title and midi file title, but you should use \bookOutputName to control the resulting filename:

\header {
  title = "File title"
  midititle = "midi title"
}
music = \relative c' {
  c1
}
\book {
  \bookOutputName "pdf_file_only"
  \score {
    \new Staff \music
  \layout {}
  }
}
\book {
  \bookOutputName "midi_file_only"
  \score {
    \new Staff \music
  \midi {}
  }
}