The purpose of this historical study was to investigate the life experiences of Marian Erdman, specifically her use of music in military hospitals. The work of Marian Erdman, as a hospital recreation worker for the American Red Cross from 1945 through 1948, provides personal insights into the role of musicians and music in military hospitals at the close of World War II. Questions addressed by this biographical study include (1) What were the professional experiences of Marian Erdman? (2) What were her views regarding the purpose and function of music in hospitals during the post-war era? (3) Did the Red Cross provide guidelines regarding the purpose and use of music with patients?, and (4) How did the events of the mid-1940s contribute to the formation of music therapy as an organized profession?