The Leonard Berkowitz Collection documents Berkowitz's musical and academic career during his tenure at California State University, Northridge, from the mid-1960s through the early 1980s. The collection includes musical scores and audio recordings composed and produced by Berkowitz, as well as works by other composers. The collection has been divided into three series: Series I, Musical Scores by Leonard Berkowitz (1956-1973, 2000), Series II, Musical Scores by Other Composers (1914-1982), and Series III, Audio Recordings by Leonard Berkowitz (1962-1998).
Series I, Musical Scores by Leonard Berkowitz, has been divided into three subseries. Subseries A, Ensembles of Six or More Instruments (1963-1967), consists of conductor's scores and instrumental parts. His works are characterized by dense harmonies and instrumentation to create dramatic textural contrasts. Berkowitz uses free 12-tone compositional style and bimodality, as well as passages derived from the octatonic scale and other non-diatonic scales. Subseries B: Ensembles of Five or Less Instruments and Solo Works (1956-1973, 2000), consists of largely contrapuntal works, with strong rhythmic motives and disjunct melodies reminiscent of Paul Hindemith’s style. Subseries C: Vocal Works (1964-1969), consists of compositions influenced by Renaissance madrigals and the chorales of J.S. Bach. The syllabic melodies of Berkowitz's vocal works are much more conjunct than those of his instrumental works. Each subseries is arranged chronologically, with instrumental parts in score order. Undated compositions are arranged alphabetically by composition title, and placed at the rear of the series.
Series II, Musical Scores by Other Composers, contains a small selection of music with notes on compositional styles, harmonic and structural analysis, and rehearsal notations penciled by Berkowitz. This series is arranged alphabetically by composer.
Series III, Audio Recordings, consists of the compositions of Leonard Berkowitz in eight volumes. Dates in this series reflect the date of recording and are arranged by volume number.