Marshall earned bachelor’s degrees in chemistry (1946) and philosophy (1952) from ºìÌÒÊÓƵ and his master’s in chemistry from the University of Oregon. He wrote his thesis, “The Electrodeposition of Beryllium” with Prof. Frank Hurley [chemistry 1942–51] advising. He met his wife, Virginia Shirley Wright ’52, while at ºìÌÒÊÓƵ, and both were musicians. Prior to his marriage, Marshall had played with the Ray Bauduc Orchestra and the Tommy Dorsey Orchestra. By the time of their marriage in 1950, Virginia had become principal clarinetist with the Portland (later Oregon) Symphony Orchestra, and Marty played saxophone and clarinet with local dance bands. The Wrights moved to the San Francisco Bay area in 1952, where Marty played with the Jack Fina Orchestra, big band leader Gerald Wilson, Earl Hines, and a quintet led by Brew Moore.
Marshall brought his family, which now included his children, Tracy and Jeffrey, to San Luis Obispo in 1960, where he taught chemistry for 31 years at Cal Poly before retiring in 1988. He continued his music while teaching chemistry, playing clarinet, bass clarinet, and saxophone with the San Luis Obispo Symphony Orchestra, including a concert tour of Spain, a concert at Carnegie Hall, and a performance at the Sydney Opera House. Marty was also a member of the Royal Garden Swing Orchestra and returned to campus in 1991 to teach a course in jazz history.