Operas 397 World War, 1939-1945 312 Symphonies 283 Excerpts 272 History 254 Teaching 168 Aids and devices 166 instructional materials 166 Piano music 163 Instruction and study 159 Ballets 142 Orchestral music 137 Interpretation (Phrasing, dynamics, etc.) 118 Sonatas (Piano) 116 Concertos (Piano) 115 Music 108 Production and direction 97 Criticism and interpretation 93 Music rehearsals 84 Active learning 81 Performance 81 Overtures 77 African Americans 72 Opera 71 Composers 69 Concertos (Violin) 67 Conductors (Music) 66 Social conditions 50 Civil rights 49 Pianists 47 Choreographers 46 Politics and government 46 Violin 46 Sonatas (Violin and piano) 45 Study and teaching 41 Suites (Orchestra) 41 Cello 40 Education, Primary 39 History and criticism 39 Ballet 37 Violin music 37 Cello music 36 Concertos (Cello) 36 Modern dance 35 Analysis, appreciation 34 Civil rights movements 34 Race relations 34 Piano 32 Treatment 32 Social life and customs 31 Solo with piano 31 Symphonic poems 31 Legal status, laws, etc 30 Musicians 30 Streaming video 29 Early childhood education 28 streaming video 28 Middle school education 27 Segregation 27 Waltzes 27 early childhood education 27 Education, Secondary 26 Social aspects 26 Choreography 25 Choruses, Sacred (Mixed voices) with orchestra 25 Violinists 25 secondary education 25 Dancers 24 Education 24 Manners and customs 24 Sociology 24 Music appreciation 23 Study and teaching (Middle school) 23 Women 23 World music 23 Families 22 Piano trios 22 sociology 22 Ballet dancers 21 Civil rights demonstrations 21 String quartets 20 Violin and piano music 20 Conducting 19 Musical analysis 19 Oratorios 19 Presidents 19 Singing 19 Dance 18 Economic conditions 18 Education, Elementary 18 Singers 18 Sonatas (Violin) 18 Song cycles 18 Sopranos (Singers) 18 Suites (Piano) 18 Development 17 Environmental aspects 17 Excerpts, Arranged 17 Piano music, Arranged 17 Songs (High voice) with orchestra 17