Scores owned by percussionist and conductor, Jan Williams. The majority of the scores were marked by Williams for use in performance. Some scores bear inscriptions from composers to Williams.

Scores and parts for solo percussion and percussion with other instruments. Most of the items bear Pugliese's performance markings. Others bear inscriptions from the composers to Pugliese. The collection also includes works composed or arranged by Pugliese.

The collection contains approximately 1300 scores, half of which bear markings entered by Mikhashoff or his colleagues in preparation for performance. The collection includes manuscripts and print publications, both originals and reproductions.