This study investigates the role of religious politics in the dismissal of Mason in 1845. Related questions are (a) How volatile an issue was religious sectarianism during the early days of music in the Boston schools? (b) What were the religious backgrounds and convictions of the School Committee members responsible for dismissing Lowell Mason in relation to those of Mason himself? and (c) Does evidence support religious controversy as playing a significant role in Mason's dismissal? Members of the Committee on Music, a subcommittee of the Boston School Committee, gave cryptic reasons for Mason's dismissal, reasons that have left modern researchers to little more than conjecture. One of the accusations against Mason, both in a journal a year earlier, and from a member of the Committee on Music, suggests that he had hired assistants with an eye to religious favoritism. Researchers have regarded that accusation as probably insignificant. However, further study of Boston's volatile religious climate, and the spiritual convictions of Mason and those who rejected him, point to religious animosities as a substantial factor impacting his departure from the schools.