When Carnegie Library of Pittsburgh opened in 1895, 2,000 of its 16,000 volumes were related to music. In fact, the very first materials the Library purchased - even before the foundation was laid - were music scores and music literature.

In 1890, Charles Scoval, music critic for The Pittsburgh Dispatch, suggested that the extensive musical library of the late Karl Merz be purchased for Carnegie Library. Born in Germany, Merz (1834-1890) was a well-known music instructor and an internationally esteemed authority on music history and theory. He taught at Oxford College and was head of the Music Department at the University of Wooster in Ohio. He was a contributor to the national periodical Etude, and chief editor of Brainard's Musical World, a leading American musical journal of the 19th century. He composed operettas, sacred pieces, choruses and songs, dance music, and violin pieces.

The 81 donors to the Merz Purchase Fund included many well-known members of Pittsburgh's industrial and music communities, such as Andrew Carnegie, Henry Clay Frick, Mrs. William Thaw (mother of Harry Thaw), Charles C. Mellor, Charles C. Scaife (president of the William B. Scaife & Sons Company, Pittsburgh's oldest manufacturing establishment of that time), W.L. Scaife (brother of Charles C.), Mrs. C.L. Magee (widow of Pennsylvania Senator Christopher Lyman Magee), J. Kaufmann & Brother (uncles of Edgar J. Kaufmann of Kaufmann's Department Store), and Ethelbert Paul Nevin Jr. (son of Pittsburgh composer Ethelbert Nevin). The fund of $1,500 was used to acquire the 1,450 volumes of the Merz collection, which were stored in the Thaw residence downtown until the Library opened.

The next major acquisition came in 1912 when the Library purchased 1,000 musical scores to meet the needs of the average music student. This was the only systematic purchase of music materials until 1938, when Ralph Munn, then director of CLP, established a consolidated music collection at the request of a group of Pittsburgh musicians. Irene Millen was soon appointed music librarian. She gathered together music scattered throughout the library system and made a collection more easily accessible to the public.

From those earliest days through the present, the local music community's support has been invaluable to the Library. Donations of printed music and music literature served as the foundation of the Library's offerings for decades before the Music Department was created in 1939. Those gifts were essential to establishing the Music Department as a resource for working musicians, music students and music enthusiasts. The personal papers and scrapbooks that compose the Music Department's Special Collections form an essential resource documenting Pittsburgh's musical life since the late 18th century.

The Music Special Collections contain more than 80 distinct collections. The items in these collections come from Pittsburgh musicians and composers, music organizations and societies, music educators and administrators, and music critics and journalists, primarily during the late 19th and early 20th centuries. The Collections contain a wide range of items, including scrapbooks, audio recordings, concert programs, original correspondence, manuscripts, newspaper clippings, posters, photographs, meeting minutes from music societies, legal documents, and more. Other Pittsburgh-focused collections in the Music Department include vinyl records, oral histories, CDs, and historic sheet music published in Pittsburgh.