Current research on music information retrieval and music digital libraries focuses on providing access to huge, public music collections. In this paper we consider a different, but related, problem: supporting an individual in maintaining and using a personal music collection. We analyze organization and access techniques used to manage personal music collections (primarily CDs and MP3 files), and from these behaviors, to suggest user behaviors that should be supported in a personal music digital library (that is, a digital library of an individual's personal music collection).