CHUM-FM started broadcasting on September 1, 1963, with an ERP of 18,000 watts and a transmitter and studio at 1331 Yonge Street. It aired a
classical music format, the first station in Canada to do so. On March 21, 1966, their ERP was increased to 54,000 watts. In 1968, CHUM-FM received approval for a change in its transmitter location and increase in power to 100,000 watts. The transmitter was to be moved to the top of the Manufacturer's Life Building at 250 Bloor Street East. At midnight on July 1, 1968, CHUM-FM changed formats to
progressive rock, a forerunner to the present-day
adult album alternative format, by playing a wide range of music ranging from
world music and
jazz to classical music and
folk music. The station also aired public affairs programming, such as
In Toronto. The station featured many famous Canadian radio personalities such as Larry Green, Walter Michaels, Steve Harris, Pete and Geets,
Reiner Schwarz, Larry Wilson,
David Marsden, David Pritchard and actor
Rick Moranis. On December 14, 1973, the station was authorized, along with other Toronto FM and TV stations, to move their transmitter to the top of the
CN Tower. The new transmitter was turned on on May 31, 1976, with a reduced ERP of 40,000 watts. Throughout the next two decades, CHUM-FM would usually be the highest rated station in the Toronto market, though it would occasionally alternate with CHFI, who was usually ranked a very close second, and would occasionally dip to third place behind
CFRB. The station evolved to its current
hot adult contemporary format in 1990. On May 26, 1998, CHUM-FM was granted a license to broadcast in
Digital audio broadcasting using the Eureka-147 system. The
transmitter was installed on the
CN Tower and broadcast at 1456.304
MHz with an
ERP of 5,084 watts. At the 25th Anniversary Canadian Music Industry Awards, held March 8, 2007, CHUM-FM was honoured as Station of the Year, Program Director of the year for CHUM-FM PD Rob Farina, and air talent of the year for
Roger, Rick & Marilyn. Former CHUM President Jim Waters was inducted into the Music Industry Hall of Fame that same evening. On June 22, 2007, CTVglobemedia purchased CHUM-FM and most of the other assets of
CHUM Limited, the station's owners since their sign-on in 1963, following approval by the
CRTC, while the
Citytv stations were sold to
Rogers Communications. On June 23, 2008, Rick Hodge resigned from both CHUM-AM and CHUM-FM to pursue other opportunities. Roger Ashby and Marilyn Denis continued to host mornings, which would then be titled
Roger, Darren & Marilyn (when Darren B. Lamb joined the show after a stint of afternoon drive host); Lamb left the station on September 23, 2015, with mornings hosted by Ashby and Denis. After a stint at
CFRB and
CJEZ-FM, Hodge would later move to sister station
CHRE-FM in
St. Catharines, where he remained until his retirement in 2019; Lamb would join CHFI in February 2016, and remained until his departure in 2021. Also in 2008, CTVglobemedia announced they had sold 1331 Yonge Street to a
condominium developer and had acquired a new property,
250 Richmond Street West, to serve as the new home of
CHUM-AM and CHUM-FM. On August 18, 2009, CHUM-FM left 1331 Yonge Street, ending 46 years at its historic home. The site would become home to a condominium complex. The new building is adjacent (and connected) to
Bell Media's headquarters at
299 Queen Street West (which also formerly housed the studios of
Citytv). Until late 2009, CHUM-FM continued to be the most listened to and most influential radio station in Canada with over 1,166,000 weekly listeners according to the BBM data released on December 3, 2007. In December 2009, AC rival
CHFI-FM became the most-listened-to radio station in Toronto. During the
2005–2009 season, CHFI continued to usually beat CHUM-FM as the top-rated radio station in Toronto, although CHUM-FM had unseated CHFI in some books. On September 10, 2010, Bell Canada announced plans to re-acquire 100% of CTVglobemedia's broadcasting arm, including CHUM Radio. When the deal was finalized on April 1, 2011, CTVglobemedia became
Bell Media, and likewise CHUM Radio became
Bell Media Radio, effectively retiring the last remaining piece of the former CHUM Limited company. CHUM Radio had been the only division of the company to retain the CHUM name following the acquisition of CHUM Limited by CTVglobemedia in 2007. On June 22, 2018, the station relaunched as
CHUM 104.5. The rebranding was intended to appeal more strongly towards women 25–54, being accompanied by a segue to hot adult contemporary, and a stronger emphasis on social media content and community interaction. ==Programming==