code: Rule Chord() {
  		return Sequence(
  				FirstOfS(ChordChordOptionalBass(),
  						ChordOptionalChordWithBass()),
  /*			OptionalS(String("(")),
  			OptionalS(BaseNote()),
  			OptionalS(ChordAccidental()),
  			OptionalS(ChordType()),
  			OptionalS(Sequence(
  					suppr("/"),
  					BaseNote(),
  					OptionalS(ChordAccidental())).label("ChordBass")),
  			OptionalS(String(")")),*/
  			ZeroOrMore(NonQuote()).suppressNode()
  		).label(Chord);
  	}
docs: chord ::= ["("] base-note [chord-accidental] [chord-type]
  ["/" base-note [chord-accidental]] [")"] *non-quote