Despite moving the FM transmitter to the top of the Prudential Tower in 1972, WWEL-FM was not very successful as a beautiful-music format. In 1978, WWEL-FM broadcast the night games of the Boston Red Sox as their flagship station (WITS, now WMEX) delivered a poor night signal in much of Metro Boston. The stations were sold to Heftel Communications, operated by Cecil Heftel, in early 1979. Heftel changed the call letters to WXKS, adopted "Kiss 108" as an identity, and changed to a disco format on February 10, 1979 at midnight. The first song played under this new format was At Midnight by T-Connection . Under Heftel, the station soared to near the top of the Arbitron ratings, and forced WBOS (which had been first in Boston with a 24/7 disco sound and had a short period of huge success with it) out of the format in early 1980.