From 1907 to 1932, when he began to pursue writing full-time, Bellamann held administrative and teaching positions at several educational institutions, including acting director of the Juilliard Musical Foundation, dean of the Curtis Institute of Music, and professor of music at Vassar College.
During his career from 1907 to 1932, Bellamann moved into a writing-focused role while also holding positions such as acting director at the Juilliard Musical Foundation, dean at the Curtis Institute of Music, and professor of music at Vassar College.