The stationhas gone through many different formats over the years. After beginning as a simulcast of WILS1320 AM as WILS-FM in 1967, the station separated programming in the late 1960s with an automated MOR format. In 1972, WILS-FM launched an automated Country format which was branded as "Hit Country", although the morning simulcast continued. In 1975, WILS-FM abandoned the Country format in favor of a 12-hour daily simulcast with WILS-AM, followed by split programming in the evening, which included an Album Rock format from 6 pm to midnight, and a Jazz format from midnight to 6 am. In 1978, WILS-FM abandoned the overnight Jazz and ended the simulcast with WILS-AM, programming the Album Rock format full-time. The Album Rock format proved to quite successful for the station, resulting in respectable ratings despite WILS-FM's 3KW signal. In August 1983, WILS-AM/FM's original owner, Lansing Broadcasting, sold the station to Sentry Broadcasting The new management made changes quickly, deciding to automate sister station WILS-AM with a Nostalgia format. In December 1983, most of the WILS-FM air staff, including the highly rated morning team of Doug Burton and Dan Ballard, were let go and replaced by announcers from WILS-AM. Four months later, on April 14, 1984, WILS-FM abruptly changed to an adult contemporary "Love Songs" format using the brand name "LS-102" to compete with top-rated WFMK. The station's ratings plummeted and would not recover for over a decade, as 101.7 FM went through unsuccessful tries at Hot AC as WKKP and WLYY, and country formats. The station also went through a number of ownership changes during this period. Sentry Insurance dissolved their radio division and sold WILS to Northstar Broadcasting in 1986, and after going through an upper-management shakeup, Northstar sold the station to its current owner, MacDonald Broadcasting, in 1989. In the spring of 1995, WILS-FM became WHZZ "Z101.7," restoring the CHR/Top 40 format to the Lansing airwaves after 94.9 WVIC-FM dropped its longtime CHR format to compete with country market leader WITL. Z101.7 was frequently criticized by CHR aficionados for featuring an overly conservative, adult-oriented playlist heavy on Hot AC chart currents and 1980s and 1990s gold, but the station enjoyed good Arbitron ratings during its run and even reached #1 overall at least once. On September 13, 2005, WHZZ unexpectedly flipped to adult hits as "Mike FM". Two days after WHZZ's flip, the CHR format was picked up by 97.5 WJIM-FM.
