In 1969, he moved to CKGM's sister station, CKGM-FM. Marsden was instrumental in switching the station's format from beautiful music to free form progressive rock. In 1973, Marsden returned to Toronto with his new, completely different on-air persona at CHUM-FM. He left the station in February 1975 to devote more time to his radio commercial production company, but mainly because of the tight playlist CHUM-FM was making their DJs follow. Marsden refused to follow a playlist and left shortly after it was instituted. He eventually returned as an on-air personality at CHIC-FM shortly before it was transformed into CFNY.