code: Rule Lyrics() {
  		return ZeroOrMore(FirstOfS(LyricsSyllableBreak(), LyricsNextBar(),
  				LyricsHold(), LyricsSkipNote(), LyricsNbsp(), LyricsDash(),
  				LyricsSyllable(),
  				SequenceS(LineContinuation(), Eol())))
  			.label(Lyrics);
  	}
docs: lyrics ::= *(lyrics-char / lyrics-syllable-break / lyrics-next-bar
  / lyrics-hold / lyrics-skip-note / lyrics-nbsp / lyrics-dash / tex-escape)