Opera MUSIC 138 Production and direction 123 Genres & Styles 112 Operas 93 Criticism and interpretation 61 Music 57 more ... History 56 History and criticism 56 Printed Music 48 Excerpts 38 Instruction & Study 32 Voice 32 Lyrics 30 Vocal 30 Philosophy and aesthetics 28 Librettos 23 Singers 22 Social aspects 22 Oper 21 Theater 19 General 18 Opera & Classical Scores 17 Singing 17 Dramaturgy 16 Composers 15 Performances 15 Libretto 14 Music and literature 14 Political aspects 11 less ...