The Heiden mss., ca. 1922-1998, consist of the of the music manuscripts, sketches, pencil scores and ink manuscripts, programs, clippings, and professional and personal correspondence of Bernhard Heiden (1910-2000) and his wife, Cola de Joncheere (1910-1999).
The Halleck mss. II, 1924-2010, consist of documents, photographs, and materials by and about congressman Charles A. Halleck acquired individually from various sources.
The Nettl mss., 1927-1967, consist of letters of Paul Nettl, 1889-1972, musicologist, during his residence at Westminster Choir College, Princeton, New Jersey, and at Indiana University, Bloomington, Indiana.