The Eastman theory faculty pursues a broad range of research interests, including Schenkerian theory, studies in the theory and analysis of 20th-century music, history of music theory, musical perception and cognition, computing and music, and jazz and other popular and ethnic musics. An annual lecture series serves to expand research horizons still further. Guest lecturers have included Charles Burkhart, Edward T. Cone, Allen Forte, David Huron, Jonathan Kramer, David Lewin, Leonard B. Meyer, Carl Schachter, Carol Krumhansl, and Joseph Straus. Student-organized theory symposia provide opportunities for students to present papers and share research in progress. Graduate students also edit and publish, with the assistance of an editorial board of prominent music theorists, a juried music theory journal entitled Intégral.

Technological support for theoretical research is provided by the Multimedia and Research Computing Lab, which gives students the chance to learn and develop software for in-house and Internet use. It is used in connection with courses on developing web pages, learning multimedia programs, programming in C, C++, Java, and other languages, using MIDI, doing research in acoustics, and effecting individual research. The lab is equipped with its own servers. Vital support for theory scholarship also is provided by the Sibley Music Library, which houses an extraordinary collection of historical treatises on music theory, manuscript letters, and first editions, and maintains active subscriptions to more than 650 periodicals.