Generating multiple PDFs from one lilypond file (and naming them appropriately)

When you write a large piece including multiple instruments, you probabily also want to generate scores for each instrument. You can make lilypond create multiple PDFs from one .ly file by simply adding mupltiple \book {...} secions in the file. Each such block will be converted into its own PDF, named filename-1.pdf, filename-2.pdf, etc. The \book {..} block typically looks like (note that the \header section needs to come after the score and after a staff, otherwise lilypond will fail with an error message...)

\book {
  \score {
    \new Staff << \va >>
  }
  \header {instrument = "Viola"}
}

To have some control about the naming of the output files, you can use

    #(define output-suffix "VcB")

to define a suffix for the filename. The number will still be added, so the filename for the \book(s) after this definition will be filename-VcB-3.pdf, etc.

\version "2.24.0"

%% http://lsr.di.unimi.it/LSR/Item?id=389

\paper {
  indent = 0
  tagline = ##f
}

vI = \relative c'' { g8 a b4 c d | e2 e,8 e( g4) }
vII = \relative c' { c4 d e f | g f d c }
va = \relative c' { \clef "tenor" c2 c2~ | c1 }
vcb = \relative c { \clef "bass" c4 b a g | f g a c }


\header { title = "Multiple Books in one score" }

% The output file will be named after the source file
% (default behavior)

\book {
  \score {
    \new Staff << \vI >>
  }
}

% The output will now be called *-VI-1.pdf
#(define output-suffix "VI")
\book {
  \score {
    \new Staff << \vI >>
  }
  \header {instrument = "Violino I"}
}

% The output will now be called *-VII-2.pdf
#(define output-suffix "VII")
\book {
  \score {
    \new Staff << \vII >>
  }
  \header {instrument = "Violino II"}
}

% The output will now be called *-Va-3.pdf
#(define output-suffix "Va")
\book {
  \header {instrument = "Viola"}
  \score {
    \new Staff << \va >>
  }
}

% The output will now be called *-VcB-4.pdf
#(define output-suffix "VcB")
\book {
  \header {instrument = "Violoncello e Basso"}
  \score {
    \new Staff << \vcb >>
  }
}

% The output will now be called *-FullScore-5.pdf
#(define output-suffix "FullScore")
\book {
  \header { }
  \score {
    \new StaffGroup <<
      \new Staff = vISt << 
            \set Staff.instrumentName = "Violino I" 
            \set Staff.shortInstrumentName = "V.I" 
            \vI >>
      \new Staff = vIISt << 
            \set Staff.instrumentName = "Violino II" 
            \set Staff.shortInstrumentName = "V.II" 
            \vII >>
      \new Staff = vaSt << 
            \set Staff.instrumentName = "Viola" 
            \set Staff.shortInstrumentName = "Va." 
            \va >>
      \new Staff = vISt << 
            \set Staff.instrumentName = \markup \column {"Violoncello" "e Basso"}
            \set Staff.shortInstrumentName = "Vc/B." 
            \vcb >>
    >>
  }
}