The station began in 1949 as CJRT-FM at Toronto Metropolitan University (then known as the Ryerson Institute of Technology). Its purpose was to train radio and television broadcast students. In 1964, with professional staffing, it began broadcasting an eclectic mix of educational programming, classics and jazz. In the mid-1970s, faced with financial constraints and the possibility of having to relinquish its license, ownership was transferred to CJRT-FM Inc., a not-for-profit corporation, to ensure its survival.

The Ontario government under Premier Bill Davis provided 60 per cent of its funding; the balance came from donations from listeners, corporations and foundations. In 1996, it was transformed again when the provincial government reduced its annual operating stipend from $1.3 million to zero, leaving the radio station to find its niche as a self-sustaining broadcaster in one of North America’s most crowded radio marketplaces.

Since then, the station has expanded its mission and executed a wide range of initiatives to enrich the cultural, educational and community experience of its listening audience. This included the change to a 24-hour jazz format in 2001.

With its all-jazz format and programs targeted toward supporting emerging artists, education and even music therapy, the station has earned a favoured place in the community. JAZZ.FM91 also has listeners well beyond the borders of Ontario, extending its reach across the country, into the U.S., and even reaching international audiences.

Providing youth programs and partnering with educational institutions, JAZZ.FM91 gives opportunities for thousands of promising young students and emerging artists to gain experience in music and broadcasting through workshops, internships, scholarships, and jazz-related content and programs. JazzologyJazz 4 Kids and the JAZZ.FM91 Youth Big Band are some of the programs and resources available to youth interested in expanding their knowledge of jazz.

JAZZ.FM91 also relies heavily on its team of volunteers. This dedicated group of people, many of whom have volunteered at the station since its earliest days, play a critical role in the smooth running of fundraising and events. Currently, the station has 90 active volunteers.