Edward Colby (1912-2006) was hired as Stanford's first Music Librarian in 1949 after he came to the attention of Professors W. Loran Crosten, Chair of the Music Department, and Leonard G. Ratner. When Colby arrived, the Music Department was located in the Knoll which now houses the Center for Computer-Assisted Research in Music and Acoustics (CCRMA), and which had first served as the residence of Stanford President Ray Lyman Wilbur and his family from 1918-1943. The collection consisted of approximately 800 books and scores and some 78-rpm recordings which were stored in two small rooms on the third floor. In 1948 Nancy Bonnin, wife of a scholar in Germanic Studies, had been appointed to supervise the small collection that had been pulled from the main library along with some reference sources from the Memorial Library of Music. Colby was the primary architect of the Music Library's collections, having seen its expansion through its first 28 years.

After retiring in 1977, Colby was succeeded by Jerry Persons in 1978. By this time the library had moved to the second floor of the Knoll and its collection included ca. 44,000 books and scores and 11,000 recordings. Under Persons' leadership extremely overcrowded conditions were relieved by the addition of a temporary building in the Knoll courtyard to house the stacks and provide study space. The former ballroom became the reference room and the pantry, the head librarian's office. While the building had lots of nice features including French doors that opened onto balconies, it also had some oddities. Two staff members shared a funny-shaped office that had first functioned as a gun closet.

The staff took care of a stray orange cat that had many aliases, (e.g. Ignaz, Perfect Love) but Stinky was the one that stuck. He craftily knew all the ways to get in and out of the building, including a book drop. On a wet day, you could spot him huddled under one of the ventilation hoods on the roof.

Services and staffing were increased during Persons' tenure, including the addition of a second professional position, Assistant Music Librarian. Mimi Tashiro was appointed to that position in 1982. Music Library staff became responsible for ordering and processing scores, recordings, and microform using the Research Libraries Group Information Network (i.e. RLIN), which had previously been done by staff in the main library. A close relationship was formed with other music libraries, most notably U.C. Berkeley and members of the Research Libraries Group (RLG), for cooperative purchases and other collection-related projects, including direct interlibrary borrowing and lending. Stanford joined with several large music libraries (Berkeley, Eastman, Harvard, Illinois, Indiana, Yale) to form the Associated Music Libraries Group (AMLG). Together they sought grant support to convert their card catalogs into machine-readable form. Perhaps Persons' greatest contribution was his planning of the new library in the Braun Music Center. The library moved over the winter break in 1983 and opened for Winter Quarter in January 1984, with the bulk of the collection remaining at the Knoll while the stacks were completed. Persons took leave from the Music Library to assume the position of Acting Head of the Stanford University Libraries Systems Office later that year and chose to remain in that position (he has since retired).

From 1984-1986, Elisabeth Rebman, formerly Head of the Music Cataloging Unit, served as Acting Head and in 1986, Kären Nagy was appointed Music Librarian & Bibliographer. At the time of her arrival, the library's collection numbered some 66,000 books and scores, and 26,000 recordings. During Nagy's tenure the position of Operations Manager was created and the former Music Cataloging Unit, which was part of the Catalog Department, became administratively part of the Music Library and was renamed Music Technical Services, encompassing both cataloging and acquisitions. The AMLG consortium continued to receive grant funding for conversion of their catalogs. The library survived the 1989 Loma Prieta Earthquake virtually unscathed except for fallen card catalogs with a few broken drawers, and books, scores and other materials which had scattered off their shelves. In 1990 Nagy moved to the main library to serve as the Acting Director of Collections and Public Services and was later appointed to that position permanently. She then became Deputy Director of the University Libraries and left the libraries to serve as Executive Dean of the School of Humanities & Sciences.

With Nagy's departure, the administrative structure of the Music Library was altered. Barbara Sawka, Curator of the Archive of Recorded Sound, was named Acting, and later permanent Head of the Music Library and Archive. As part of this change Mimi Tashiro was promoted to Music Bibliographer in 1992 with responsibility for the collections in the Music Library. In 2001 Sawka chose to retire and in 2003, Jerry McBride began his appointment as Head of the Music Library and Archive of Recorded Sound. At the time of his arrival, the library contained more than 112,000 books and scores and 32,000 sound recordings. McBride retired in 2020, and in 2021, ethnomusicologist and archival researcher Tamar Barzel was hired as the new Head, Music Library & ARS.

Over the years, the Music Metadata Unit (formerly the Music Cataloging Unit, and Music Technical Services) has been served by many outstanding librarians. Among them are Mia Rode, Garrett Bowles, Peggy Meyers, Elisabeth Rebman, Marlene Wong, Mimi Tashiro, Jeffrey Earnest, Kevin Freeman, Philip Schreur, Nancy Lorimer, Raymond Heigemeir, Kevin Kishimoto, and Clare Spitzer. In 2019 the Archive welcomed Nathan Coy as Sound Archives Librarian. 

The library's paraprofessional staff has included several music doctoral students who have gone on to careers in librarianship, including Lynne Toribara, Kent Underwood, Philip Schreur, and Eunice Schroeder. Rebecca Lasher Wesley, who worked as a library assistant, would leave and later return to Stanford as Head of its Math and Computer Science Library. Others who have worked in the Music Library and ARS and made valuable contributions include Erna Wilson, Ida Kattenberg, Jean Kan, Marianne Bahmann, Katherine Bain, Lissy Bland, Gina Balestracci, Diane Westfall, Geoffrey Skinner, C. Winton Reynolds, Sheridan Schroeter, Aurora Perez, Keith Bisaillon, Ruth Escher, Stephen Escher, Anne Piascik, Riva Bacon, Richard Powers, Mie Araki, Liam Harty, Benjamin Bates, Anna Graves, Frank Ferko, and Vincent Kang.

Stanford graduates in music who went on to become music librarians include Gordon Rowley, George Hill and Tom Moore.

~ Mimi Tashiro ~