\score {
  \header {
    title = "Allein Gott in der Höh sei Ehr"
    composer = "Prätorius, Mich."
  }
  \new StaffGroup <<
    \new Staff <<
      \new Voice = "sopran" << \global \sopranMelodie >>
      ifdef(`STR_1', \new Lyrics \lyricsto "sopran" \sopranTextI )
      ifdef(`STR_2', \new Lyrics \lyricsto "sopran" \sopranTextII )
    >>
    \new Staff <<
      \new Voice = "alt" << \global \altMelodie >>
      ifdef(`STR_1', \new Lyrics \lyricsto "alt" \altTextI )
      ifdef(`STR_2', \new Lyrics \lyricsto "alt" \altTextII )
    >>
    \new Staff <<
      \new Voice = "maenner" << \clef "bass" \global \maennerMelodie >>
      ifdef(`STR_1', \new Lyrics \lyricsto "maenner" \maennerTextI )
      ifdef(`STR_2', \new Lyrics \lyricsto "maenner" \maennerTextII )
    >>
  >>
  \layout {
    indent = #0
    \context {
      \Score
      %% no bar lines in staves or lyrics
      \hide BarLine
    }
    %% the next two instructions keep the lyrics between the bar lines
    \context {
      \Lyrics
      \consists "Bar_engraver"
      \consists "Separating_line_group_engraver"
    }
    \context {
      \Voice
      %% Comment in the below "\remove" command to allow line
      %% breaking also at those bar lines where a note overlaps
      %% into the next measure.  The command is commented out in this
      %% short example score, but especially for large scores, you
      %% will typically yield better line breaking and thus improve
      %% overall spacing if you comment in the following command.
      \remove "Forbid_line_break_engraver"
    }
  }
}