Detroit had 99.5 WOWF "Wow FM" as Talk from roughly January to May 1993 (after CHR WDFX, before Country WYCD) and 102.7 WDMK "Kiss FM" as mainstream AC during the summer of '99 (after Classic Rock WWBR "The Bear" and before Radio One flipped Kiss to Urban AC; they even had Delilah). Both so short-lived I'm virtually 99% sure they were just smokescreens meant to catch the competition off guard. Going farther back, there was also 93.1 WDRQ's time as a Talk station from roughly June 1971 to March of '72 before going Top 40.
To the west, there was 105.3 WCXT Hart's (now WHTS) very short time as Dance "105-3 The Whip" also during the summer of 1999. IIRC Nancy Waters (then-owner and one of the first Black female station owners in the business) leased the frequency to a Muskegon nightclub, then took it back and reinstated the former automated "Lite Mix" Soft AC format once the nightclub failed to keep up the payments. If I'm not mistaken, the format flipped in May or June (after I'd already gotten out of college for the summer) and reverted to AC by Thanksgiving. As it was, it was a 100,000-watt signal with half its coverage area serving the fish in Lake Michigan, and the other half serving mostly deer and grizzly bears in the central western Lower Peninsula with Whitney/Britney/Mariah/Madonna dance mixes and stuff like Mousse T's "So Horny." How could it not work? (heavy sarcasm)