class Lily_lexer;
class Lily_parser;
class Listener;
-class Lookup;
class Lyric_combine_music;
class Lyric_combine_music_iterator;
class Lyric_engraver;
class Scale;
class Scheme_hash_table;
class Scheme_engraver;
+class Scm_module;
+class Scm_variable;
class Score;
class Score_engraver;
class Score_performer;