If you walk into a restaurant and it's live-music Friday and the Alltunators are playing, you should feel pretty good about that. Their presence will enhance your meal, and they may put just enough hootenanny in your heart to compel you to throw a buck in their tip jar at the end of the night. But it's just not the sort of music you go out of your way for. The band's latest, Nation of Three, is background music, too. To be clear, there's no doubt the band is competent: The members can hit notes and approximate the sound of an old-timey mining-town saloon, plucking at fiddles and banjos and keeping the harmonies simple. But, you know, that mine is sort of stripped bare at this point, isn't it?