The purpose of this case study research was to explore the professional identities of second-stage music teachers, or those in years 4-10 of teaching, focusing primarily on how their identities were sustained or neglected. Participants were two second stage music educators teaching in middle school (grades 6-8) music classrooms and taught primarily instrumental (band and orchestra) ensembles. Data were collected in individual formal interviews and on a password protected blog. This article reports on the four themes developed through cross-case analysis: (a) Professional Development, (b) Parent Involvement, (c) Student Achievement/Enjoyment, and (d) Professional Peers. Participants experienced professional development dichotomously: informal/formal, choice/mandatory, subject-specific/subject-neutral, personalized/general, and perpetual/ bounded. Students and their parents played prominent identity-reinforcing roles for the participants. Student achievement and enjoyment, especially when recognized by others, also reinforced participants' professional identities. Participants' professional peers were almost exclusively other music teachers. Implications for research and K-12 and university practice are included.