It's not always easy to sum up a career, let alone a life's ambition, in five words, but "the road goes on forever," Robert Earl Keen's calling-card anthem, just about does it. You can complete the lyric with the next five words, the ones routinely shouted back at Robert by thousands of fans a night—"and the party never ends!" It's the journey that makes Robert Earl Keen tick. Some people take up a life of playing music with fame and fortune in mind, but from the get-go Robert Earl Keen just wanted to write and sing his own songs, and to keep writing and singing them for as long as possible. "I thought of it in terms of having a really, really good career and writing some good songs," he says, "and getting on stage and having a really good time." What other Texas songwriter sells his own brand of Bloody Mary mix? Robert Earl Keen comes to Michigan with a new bluegrass album, "Happy Prisoner."