The Judith Rosen Collection consists of music researcher and author Judith Rosen's personal collection of audiocassette recordings, many of which are unpublished. Rosen, who has written a highly-regarded biography of composer Grazyna Bacewicz
, as well as articles for High Fidelity/Musical America and the New Grove series, is a current or former board member of The Women's Philharmonic, Women's Philharmonic Advocacy, the Arnold Schoenberg Institute, the Los Angeles Chamber Orchestra, and the Ojai Music Festival. While there is a mix of styles in the collection's music performances, the majority is new music and the work of twentieth century composers. Given her association with the Women's Philharmonic, it is no surprise that the collection is also strong on women composers and musicians. Among the live and studio recordings that comprise the majority of the collection, there are radio programs, interviews, and conference presentations. Many appear to be promotional demos and other semi-commercial issues. Original sources are rarely credited, and some tapes may be copies of commercially released material. There are a handful of published cassettes retained in the collection as well. The tapes have been alphabetized, for the most part by composer.
Perhaps the most significant recordings here are from the Freeman Musicale series of lecture/performances named for philanthropist Betty Freeman. These salons (also known as the Music Room sessions) took place both in Freeman's home in Beverly Hills and later at the Rosen's in Encino, and featured many of the leading lights in the contemporary composition world, from Elliot Carter, Pierre Boulez and Sylvano Bussotti to Gyorgy Ligeti, Mel Powell, and Roger Reynolds, even jazz musician Anthony Braxton. Other recordings in the collection were commissions by Freeman, such as Kaija Saariaho's opera L'Amour de Loin. The collection also contains lectures from the National Congress on Women in Music, various interviews with the Seeger family (Barbara, Charles, Mike, Peggy) about Ruth Crawford Seeger, and several recordings of Rosen herself in lectures or interviews, as well as her husband Ron Rosen's Sixtieth Birthday Concert featuring premiered works by William Kraft, Leonard Rosenman and Vernon Duke.