KOSI

On March 3, 1968, KOSI-FM officially signed on the air, as the FM counterpart to KOSI in Aurora (now KEZW).[2]

KOSI-AM-FM both aired a beautiful music format, with some hours simulcasting and some hours separately programmed. The stations were owned by William L. Armstrong, who would later become a Republican Congressman and two term U.S. Senator. Armstrong sold KOSI-AM-FM to Westinghouse Broadcasting in 1981. KOSI became KEZW in March of that year, carrying an adult standards format, while KOSI-FM continued playing easy listening music.

In 1988, Westinghouse sold KOSI and KEZW to D&D Broadcasting, Inc. for $15.5 million.[3] In the 1980s, many easy listening stations found their audiences getting older, and not as attractive to advertisers; in response, KOSI began adding more vocals and deleting some instrumental songs.

On February 6, 1990, KOSI made the transition to soft adult contemporary music, with an all-vocal playlist.[4] By the early 2000s, KOSI, along with other Soft AC stations, began adding more upbeat titles to the playlist, making the transition to a mainstream Adult Contemporary format.

In 1989, KOSI and KEZW were sold to Shepard Communications of Grand Rapids. Then in December 1992, Tribune Broadcasting acquired KOSI and KEZW for $19.5 million.[5] In December 2002, the two stations were sold to Entercom. From 2007 to 2011, KOSI aired the syndicated Delilah radio show in the evening. Delilah has since been replaced with local programming.

On July 14, 2015, as part of a merger with Lincoln Financial Media, and to be in compliance with ownership caps and total market revenue limits, the Department of Justice required Entercom to spin off KOSI, KYGO-FM, KKFN and KEPN to Bonneville International in exchange for Bonneville's KSWD in Los Angeles (now KKLQ). This resulted in KOSI and KEZW being separately owned for the first time. Both Bonneville and Entercom began operating their new clusters via Time Brokerage Agreements on July 17, 2015, until the transaction was consummated on November 24, 2015.[6]