By Nathan Poppe Entertainment Writer npoppe@oklahoman.comMarcus Hummon writes hit songs but just not always for himself. Hummon is based in Nashville, Tenn., and has written commercially successful hits for Rascal Flatts, the Dixie Chicks, Garth Brooks and a lot more country artists. This weekend, he'll be workshopping and writing alongside several Okies and other Nashville musicians during the Oklahoma Songwriter's Festival.Read more on NewsOK.com