The Tams-Witmark Music Library was established in 1925 through the merger of the Arthur W. Tams Music Library and the rental library of M. Witmark & Sons. The Tams-Witmark (Original Library of Congress Collection) contains music (manuscript and printed scores) that was being performed in the United States during the late nineteenth and early twentieth centuries. The bulk of the materials are nineteenth-century English, French, German and Italian operas and operettas, the majority in full score, with some instrumental parts. Most of the scores have been annotated with cuts and performance markings, and some feature reduced or non-standard orchestrations. The collection also contains a small amount of concert music, including secular and sacred choral works, patriotic music, symphonic scores, and incidental music. Herbert is well-represented in the collection, and his materials are particularly significant because they include not only finished manuscripts but also sketches and scores for numbers cut from various productions. Of special interest are the numerous scores, parts, and holograph sketches of Victor Herbert's 1912 opera Natoma.

The Tams-Witmark Music Library was established in 1925 through the merger of the Arthur W. Tams Music Library and the rental library of M. Witmark & Sons. Formed in 1883, the Tams Music Library specialized in sacred music and opera and by the 1920s, it grew into one of the largest libraries of its kind. The Witmarks entered the music publishing business in 1885 and started their own rental library in 1898. It handled mostly popular operas and musicals, including those of Victor Herbert, Reginald DeKoven, and George M. Cohan. In 1969, the Tams-Witmark Music Library dispersed a large part of its older materials among five libraries: the Library of Congress, the University of Wisconsin at Madison, Princeton University, the Eastman School of Music, and Westminster Choir College. The Tams-Witmark-Princeton Collection contains music (manuscript and printed scores) that was being performed in the United States during the late nineteenth and early twentieth centuries. Most of the opera and operetta material consists of piano-vocal scores and orchestral parts, many of which have been annotated with cuts and performance markings; some feature reduced or non-standard orchestrations.

Warner/Chappell Music is an American music publishing company that traces its establishment to Chappell & Co. in London in 1810. Warner/Chappell grew in part due to its acquisition of other music publishers, many of which played prominent roles in New York City's Tin Pan Alley and in the production of shows on Broadway and elsewhere. The Warner/Chappell Collection primarily consists of scores for musicals, most intended for Broadway, but some for film, television, and other venues. The majority of the scores are manuscripts in the hands of arrangers, songwriters, and copyists, and includes combinations of full scores, piano-vocal scores, parts, and lyric sheets. The collection also contains manuscripts for popular songs and works for orchestra, band, and chamber ensembles, as well as a small number of business papers and cancelled checks. Victor Herbert's music manuscripts include several popular songs, concert music and arrangements, and selections from "The Dream Girl," "Eileen," "The Enchantress," "Her Regiment," "Naughty Marietta," and "Orange Blossoms."

The collection includes music manuscripts, printed music, papers, photographs, electronic media, posters, realia, and recordings acquired by the American Society of Composers, Authors, and Publishers (ASCAP) relating to some of its members from the organization's inception to the present day. Included also are materials relating to the ASCAP Foundation's educational and professional programs, and a few archival materials pertaining to the parent ASCAP organization. Victor Herbert was one of the founders of ASCAP in 1914, and served as vice president of the organization until his death in 1924.

John McGlinn (1953-2009) was an American conductor and musical historian best known for his reconstructions, performances, and recordings of original Broadway orchestrations. Victor Herbert is particularly well-represented among these materials. In addition to scores, the collection includes a fair amount of librettos, particularly for productions by Victor Herbert, as well as narrative script material for special events.

Charles Miller was an arranger, orchestrator, copyist, and editor who worked with many prominent Broadway composers of the early twentieth century. The collection primarily contains holograph and manuscript piano-vocal scores and scores for piano by Victor Herbert, Victor Jacobi, Werner Janssen, Jerome Kern, Fritz Kreisler, and Vincent Youmans, as well as a typescript article about Victor Herbert written by Miller.

The Rose Marie and Harold Spivacke Fund Collection consists of materials purchased through an endowment that Rose Marie Spivacke established in 1982 at the behest of her husband, Harold Spivacke, who was chief of the Music Division at the Library of Congress from 1937 to 1972. The collection includes music manuscripts, printed scores, correspondence, clippings, and iconography, including music manuscripts, annotated scores, correspondence, and an inscribed photograph by Victor Herbert.

George H. Moss (1923-2009) was a local historian in Monmouth County, New Jersey, who also had an interest in early American theater. The collection consists of printed sheet music dating between 1885 and 1935, the majority of which is for American popular songs dating from 1900 to 1925. Victor Herbert is one of numerous composers well-represented in the collection.