Traditional access methods are sometimes unsatisfactory for music due to the larger number of foreign names and titles than other materials, the fact that a single musical work can exist in multiple printed and recorded editions, and the large number of variant and popular titles. In addition, portions of musical works are frequently published or performed separately with no reference to the parent work and sometimes even with a different title. Entire musical works, or selected portions, may be arranged or transcribed to create "new" entities. 
The uses of thematic catalogs (i.e. mnemonic aids, advertisements, tables of contents, guides to composers' output, inventories of library holdings, and musicological documentation) seem to indicate the need of music researchers for better description and collocation abilities than other cataloging methods can provide. D. W. Krummel has written that
[i]t is clearly appropriate for music to be identified through the stuff of which it is made, . . . [T]hematic incipits . . . offer the potential for collocation based on distinctive elements of the content.In the past, the greatest impediments to implementation of such indexing were the lack of a representation of music which would lend itself to searching and musician-friendly encoding mechanisms. Despite recent technological advancements on both fronts, however, thematic indexing has not yet become a common part of the online catalog environment.
Even though there are now many possibilities for the online representation and retrieval of music, the beneficiaries of the technology and their informational needs remain unidentified. Except for a single general survey, the music library community appears not to have taken an interest in determining patron satisfaction with current collections and services and certainly not in ascertaining it users' needs for new materials and methods.
Incipit -- The opening theme or passage of a composition or section of a composition.
Music librarian -- Person responsible for the establishment, preservation, organization, and utilization of a collection of music materials, i.e. printed music, audiorecordings.
Music research library -- A library which contains an in-depth collection in the field of music. Examples include, but are not limited to university libraries or large private or public libraries and collections.
Thematic catalog - A thematic catalog is an index to a group of musical compositions that incorporates citations of their opening notes (incipits), or principal melodic features (themes), or both. These citations may be given in various forms, such as conventional notes, neumes, tablatures, syllables, numbers, letters, or computer codes. This broad definition must be qualified, however, for in practice, defying etymology, most thematic catalogues are concerned with incipits rather than with themes as such.
Users -- People who seek information in a music research collection. They may be researchers who visit music research libraries or who use items obtained from music libraries. Users may be library staff members who retrieve information or may be persons who never visit a music research library but receive information indirectly, i.e., electronically.
This research proposal is limited to libraries listed in the Music Library Association membership list and to library users who come into the library. Unfortunately, users who access the library electronically are excluded. Future research may be directed at this group, however.
2. Barry S. Brook, Thematic Catalogues in Music: An Annotated Bibliography. (Hillsdale, NY: Pendragon Press, 1972), x-xv.
3. D. W. Krummel, "Citing the Score: Descriptive Bibliography and Printed Music," The Library, 6th ser., 9, no. 4 (1987): 336.
4. Susan M. Clegg, "User Surveys and Statistics -- The Opportunities for Music Libraries," Fontes Artis Musicae 32 (Jan. 1985), 69-75.
5. Adapted from American Library Association, ALA Glossary of Library and Information Science. Heartsill Young, ed. (Chicago: American Library Association, 1983), s.v. "Librarianship."
6. Adapted from American Library Association, ALA Glossary of Library and Information Science. (Chicago: American Library Association, 1983), s.v. "Research library."
7. Stanley Sadie, ed., The New Grove Dictionary of Music and Musicians. (London: Macmillan Publishers, 1980), s.v. "Thematic catalogue."