there is nothing stopping you from starting a multigenre station, are you familiar with John Peel? he was a BBC Radio 1 DJ that famously played ALL genres on his one DJ show, it was brilliant. He used to say, there is no genres in music, there is only good and bad music. i probably horribly misquoted a legend there.
i host my own syndicated show on the same principle, if its good, its in. With a loose theme, it makes for a much more interesting show.