I really like the show, and the theme song. It is funny as all-git-out. They have had many good singers singing it. This one is one of those I'm surprised I don't know, since apparently he's nigh enough king of country. (Me having little interest in country normally of course helps.) George Jones (wiki).
... First I thought: "he certainly sounded very different when he was young", but it turns out he sings very different from he talks.