WBMX (104.3 FM, 104.3 Jams) is a commercial radio station in Chicago, Illinois, serving the Chicago metropolitan area and Northwest Indiana. The station is owned by Audacy, Inc. and airs a classic hip hop radio format. WBMX's studios and offices are located at Two Prudential Plaza in the Chicago Loop. The station has an effective radiated power (ERP) of 4,100 watts, with its transmitter atop the Willis Tower (formerly Sears Tower). WBMX broadcasts in the HD Radio format, with its HD2 signal simulcasting the sports radio format on co-owned WSCR. From 1974 to 1988, the call letters WBMX were held by 102.7 FM, licensed to Oak Park, Illinois (now Urban AC station WVAZ). On December 4, 2017, the call letters were transferred from Boston to 104.3 FM in Chicago. History WSEL The station began broadcasting in September 1953, holding the call sign WSEL. It aired beautiful music, light classical music, recorded music and show tunes along with news reports. The station had an ERP of 40,000 watts, and its transmitter was located atop Chicago's Randolph Tower. WSEL was owned by Chicago Skyway Broadcasting Company. A previous station in Chicago had briefly operated on 104.3 MHz in 1949. WCFL-FM, owned by the Chicago Federation of Labor, broadcast from 3 to 9 p.m. as a 400-watt simulcast of WCFL, but the owners surrendered the station's license, as it was not profitable. In 1958, WSEL's transmitter was moved to the Willoughby Tower at 8 South Michigan Avenue. In 1960, the station was sold to Plough Broadcasting for $50,000, and it was taken silent. WJJD-FM The station returned to the air January 2, 1961, with its call sign changed to WJJD-FM. It was co-owned with 1160 WJJD by Plough Broadcasting. At the time, 1160 WJJD was a daytimer. WJJD-FM initially aired classical music, show tunes, folk music, and jazz. On February 15, 1965, WJJD adopted a country music format, and WJJD-FM simulcast 1160 WJJD, with WJJD-FM continuing WJJD's country programming after sunset. In 1971, the station's transmitter was moved to the Prudential Building, and its ERP was reduced to 14,100 watts. WJEZ In February 1977, the station's call sign was changed to WJEZ'. The station adopted a "beautiful country" format, playing easy listening country music, with large amount of instrumentals, in an approach patterned on the beautiful music format. In September 1978, the station adopted a "modern country" format, with a playlist that was