This was done back in the early nineties by programmer Keith Clark (now in Pittsburgh) at the Pop station he was programming in Cleveland. I can't remember the call letters, but as grunge started to hit it big alongside the hip hop from back then, he would alternate the two. I think he also worked in some R&B, too, with the idea of calling it "Pop, Rock, & Soul" or somesuch. I don't remember it being very successful, but I cheered him on for being creative.
Jim Kerr
Pollack Media Group