Dan Penn is one of my favourite characters in the soul story. As Fame's Rick Hall told Peter Guralnick in Sweet Soul Music: "Here was this kid, white, sixteen years old, singing like Ray Charles, just in love with black music. He was the real thing. He wasn't a rip-off or a fake. He knew more about black music than the rest of us put together." When Penn showed up in at Hall's fledgling studio in Muscle Shoals, he brought a song he'd written with him: "Is a bluebird blue?" which later became a hit for Conway Twitty.