Opera History and criticism 171 Music 130 Operas 128 History 112 Production and direction 67 Dramaturgy 44 more ... Criticism and interpretation 42 Singers 40 Composers 32 Philosophy and aesthetics 31 Social aspects 31 Ballet 24 Libretto 24 Political aspects 23 Dictionaries 20 Music and literature 19 Musicians 18 Librettos 17 Theaters 17 Theater 16 Performances 15 Oper 13 Opéra 13 Singing 13 Stage-setting and scenery 13 Analysis, appreciation 11 Biography 11 Women singers 10 Dramatic music 9 less ...