\score {
  \header {
    title = "Freuet euch der schönen Erde"
    poet = "Text: Philipp Spitta (1801-1859)"
    composer = "Melodie: 1693"
    arranger = "Satz: Paul Horn"
  }
  \new ChoirStaff <<
    \new Staff
    <<
      \set Score.skipBars = ##t
      \new Voice = sopran  { \global \voiceOne \sopranMelodie }
      \new Voice = alt     { \global \voiceTwo \altMelodie }
    >>
    ifdef(`STR_1',`\new Lyrics \lyricsto sopran { \textI }')
    ifdef(`STR_2',`\new Lyrics \lyricsto sopran { \textII }')
    ifdef(`STR_3',`\new Lyrics \lyricsto sopran { \textIII }')
    ifdef(`STR_4',`\new Lyrics \lyricsto sopran { \textIV }')
    \new Staff <<
      \new Voice = tenor   { \global \clef "bass" \voiceOne \tenorMelodie }
      \new Voice = bass    { \global \clef "bass" \voiceTwo \bassMelodie }
    >>
  >>
  \layout {
    indent = #0
  }
}