Operas 398 World War, 1939-1945 318 History 292 Symphonies 284 Excerpts 272 Teaching 168 Aids and devices 166 instructional materials 166 Piano music 164 Instruction and study 159 Ballets 142 Orchestral music 137 Interpretation (Phrasing, dynamics, etc.) 118 Concertos (Piano) 116 Sonatas (Piano) 116 Music 109 Production and direction 97 Criticism and interpretation 94 African Americans 84 Music rehearsals 84 Active learning 81 Performance 81 Overtures 77 Opera 71 Composers 69 Concertos (Violin) 67 Conductors (Music) 66 Social conditions 57 Politics and government 55 Civil rights 51 Choreographers 50 Pianists 47 Violin 46 Sonatas (Violin and piano) 45 Study and teaching 42 Modern dance 41 Suites (Orchestra) 41 Cello 40 History and criticism 40 Education, Primary 39 Ballet 38 Concertos (Cello) 37 Race relations 37 Violin music 37 Cello music 36 Social aspects 35 Analysis, appreciation 34 Civil rights movements 34 Social life and customs 34 Treatment 33 Piano 32 Legal status, laws, etc 31 Solo with piano 31 Symphonic poems 31 Musicians 30 Dancers 28 Early childhood education 28 Waltzes 28 Education, Secondary 27 Manners and customs 27 Middle school education 27 Segregation 27 early childhood education 27 Choreography 26 Streaming video 26 Choruses, Sacred (Mixed voices) with orchestra 25 Education 25 Violinists 25 Women 25 secondary education 25 streaming video 24 Economic conditions 23 Music appreciation 23 Study and teaching (Middle school) 23 World music 23 Ballet dancers 22 Climatic changes 22 Families 22 Piano trios 22 Civil rights demonstrations 21 Environmental aspects 21 Dance 20 Presidents 20 Singers 20 Sociology 20 String quartets 20 Travel 20 Violin and piano music 20 World history 20 Conducting 19 Musical analysis 19 Oratorios 19 Political aspects 19 Singing 19 Civilization 18 Development 18 Education, Elementary 18 Emigration and immigration 18 Sonatas (Violin) 18 Song cycles 18