Howard Bill, general manager of WBIZ-AM, launched WBIZ-FM on December 27, 1967 as a primary simulcast to its AM station after receiving the authorization green light from the Federal Communications Commission. WBIZ-FM is also one of the first radio stations in Northern Wisconsin to receive stereophonic sound in October 1974, and WBIZ-FM dropped its simulcast the following year when the station received its longtime "Z100" branding on November 3, 1975, which retained its Top 40 music format that was originally delivered from its AM station.