| A | General Works |
| AE | Encyclopedias |
| B | Philosophy. Psychology. Religion |
| BF | Psychology |
| BL-BX | Religion |
| C | Auxiliary Sciences Of History |
| D | History (Except America) |
| DA | Great Britain |
| DC | France |
| DD | Germany |
| DP | Spain - Portugal |
| DS | Asia |
| E-F | History of the Americas |
| G | Geography. Anthropology. Recreation |
| GR | Folklore |
| GV | Recreation. Leisure |
| GV1580-1799.4 | Dance |
| H | Social Sciences |
| J | Political Science |
| K | Law |
| L | Education |
| M | Music |
| ML | Literature on Music |
| MT | Musical Instruction and Study |
| N | Fine Arts |
| P | Language and Literature |
| PC | Romance Languages |
| PD | Germanic Languages |
| PE | English Language |
| PL | Chinese and Japanese Languages and Literature |
| PN | Literature (General) |
| PN1600-3307 | Drama (Films, Theater, etc.) |
| PQ | Romantic Literature (French, Italian, Spanish, Portuguese) |
| PR | English Literature (British) |
| PS | American Literature |
| PT | Germanic Literature |
| PZ | Juvenile Literature |
| Q | Science |
| R | Medicine |
| S | Agriculture |
| T | Technology |
| U | Military Science |
| V | Naval Science |
| Z | Bibliography. Library Science. Information Resources (General) |
| ML1-5 | Periodicals. Serials |
| ML12-21 | Directories. Almanacs |
| ML25-28 | Societies and other organizations (Including documents of performance organizations and individual performance ensembles associated with a particular city) |
| ML29-31 | Special collections |
| ML32-33 | Institutions |
| ML35-38 | Festivals. Congresses |
| ML40-44 | Programs (Class here programs not classed in ML25-38 or MT4-5) |
| ML45 | Circulars and advertisements |
| ML46 | Scrapbooks |
| ML47-54.8 | Librettos. Texts. Scenarios |
| ML55-90 | Aspects of the field of music as a whole |
| ML93-97 | Manuscript studies and manuscripts |
| ML100-109 | Dictionaries. Encyclopedias |
| ML110-111.5 | Music librarianship (Including cataloging, classification, etc.) |
| ML112-112.5 | Music printing and publishing |
| ML112.8-158.8 | Bibliography (Class here bibliographies of music and bibliographies of works about music) |
| ML159-3785 | History and criticism (Including biographies) |
| ML3790-3792 | Music trade (Including the sound recording industry) |
| ML3795 | Music as a profession. Vocational guidance (Including social and economic conditions of musicians) |
| ML3797-3799.5 | Musical research (Including methods of research) |
| ML3800-3923 | Philosophical and societal aspects of music, Physics and acoustics of music. Music Therapy (ML3920), Physiological aspects of music (Including metaphysics and origin of music) |
| MT 1 | General works (Including history and theory of music education. Class here general music instruction for educational levels through high school) |
| MT2.5 | Music Study Abroad |
| MT3-5 | History (by place or institution) |
| MT5-5.7 | Music Theory & Printed Pedagogical Aids |
| MT17 | Music in Special Education |
| MT18 | Music in Colleges and Universities |
| MT20-34 | Systems and Methods |
| MT35-39 | Notation |
| MT40-67 | Composition. Elements and techniques of Music |
| MT68 | Improvisation, Accompaniment and Transposition |
| MT70-74 | Instrumentation and orchestration |
| MT75 | Interpretation |
| MT80 | Embellishment |
| MT82 | Memorizing |
| MT85 | Conducting. Score reading and playing |
| MT86 | Jazz band, dance band instruction (including conducting, organization and management) |
| MT87 | Community music |
| MT88 | Administration and instruction of vocal groups |
| MT90-146 | Analysis and appreciation of music |
| MT150 | Audio-visual aids |
