WMGK can trace its origins back to 1940, when the FCC issued call letters W67PH to a new FM station owned by the
WCAU Broadcasting Company. On November 1, 1941, W67PH changed call letters to W69PH when its frequency was changed
to 46.9 MHz. WCAU-AM programming was duplicated on the FM station when it went on the air November 20, 1942 with
studios in the WCAU building at 1622 Chestnut Street, and transmitting tower atop 1616 Chestnut Street.
W69PH changed call letters to WCAU-FM on November 1, 1943 and was subsequently acquired by The Philadelphia Record
newspaper along with WCAU-AM in 1946. When the new higher band FM stations were assigned by the FCC in 1945, WCAU
was placed at 102.7 and then moved to 102.9. After a lengthy strike at the Record in 1947, the paper went out of
business and sold its assets to the Philadelphia Bulletin, which also inherited the rights to buy WCAU AM and FM.
Since the Bulletin already owned WPEN AM and FM, it sold off the less powerful 950 AM and 102.9 FM frequencies and
kept the more powerful 1210 Am and 98.1 FM stations as WCAU.
The new owner of 102.9 FM (and WPEN AM) was the William Penn Broadcasting Company, which was in turn purchased by
the Sun Ray Drug Company owned by the three Sylk Brothers. The station, now known as WPEN-FM moved into the three
story Philco building located at 2212 Walnut Street, while continuing to broadcast from 1616 Walnut Street.
In the 1950s, WPEN-FM offered a "Simplex" background music service for local businesses: While the general public
was able to hear the music and commercials being broadcast, subscribing busniesses were provided with a special box
that muted the commercials. The system was known as "Musitone" due to the high frequency inaudible tone that was
used to trigger the receiver. The FCC was not enthusiastic about the use of Simplex services and pushed for the use
of subcarrier systems which were alternate streams embedded in the main FM signal. WPEN became one of the first
stations approved for subcarrier broadcasting in 1955. For the next 20 years, it was mainly the rental of
subcarrier boxes by businesses for commercial-free music that paid for much of the WPEN-FM operations. (FM
listening was scant and commercials rare during this period.)
By 1958, WPEN-FM was transmitting from a tower atop the Rittenhouse Claridge. During the 1960s, WPEN-FM duplicated
a varied portion of the AM programming, playing "standards" the rest of the time. In 1969, a group of local
businessmen led by Martin Field purchased the WPEN stations. Through the early 1970s, WPEN-FM continued to
simulcast the AM programming around 30% of the time, still broadcasting in mono.
WPEN AN and FM were sold to Greater Media Inc. in 1975 for $4.3 million. By spring of that year, a new oldies format debuted on WPEN-AM, with a full simulcast on WPEN-FM. Finally, on Labor Day 1975, with new call letters WMGK and in full stereo, 102.9 began a separately programmed soft rock format known as "Magic 103." While a number of Philadelphia FM stations had a hard rock sound aimed at a younger audience, and others supplied easy listening aimed at an older audience, WMGK targeted 25 to 34-year olds with a mellow rock sound. The format, initailly programmed by Dave Klahr, became quite popular in the radio industry and was copied on many stations throughout the country. After a slight adjustment in 1980 by general manager Larry Wexler and program director Bob Craig to remove some album cuts for a broader appeal, Magic 103 was a top 10 station through much of the 1980s.
In 1978, the studios had moved from Philadelphia to #1 Bala Cynwyd Plaza (now known as 1 Bala Plaza) in Bala Cynwyd, and the transmitter moved from the Rittenhouse Claridge to the Roxborough antenna farm on Domino Ave. The old tower still remains atop the Rittenhouse Claridge, visible from the square below.
Around 1993, WMGK changed their long-standing name "Magic 103" to the more modern digital-sounding "Magic 102.9" but still programmed a mainstream soft rock/adult contemporary format. In the summer of 1994, with stiff competition from WBEB "B101" and WYXR "Star 104.5," WMGK decided to switch to an all 70s format, which was announced by Julian Breen on Mike Bowe's shift on July 10, 1994. Although the 70s format initailly consisted of all hits from the 1970s from easy listening to disco, by early 1995 the mix leaned towards the more classic rock songs of that era. By the fall of 1995, the Magic name was dropped after a 20 year run, and mostly classic rock songs were played. WMGK positioned itself as a "calssic hits" station, staying away from most of the harder classic rock songs. In 1997, Greater Media acquired WMMR and continued leaning softer than most classic rock stations to lessen the overlap with WMMR. Today, WMGK is the only classic rock station in the Philadelphia region.