Cass McCombs is a rustling and itinerant songwriter. He never quite feels at home in his songs, and every mention of geographic points seems to be in remembrance, passing, or consternation. In fact, McCombs often sounds more comfortable singing about hell than any location on earth, and maybe that's because his songs are usually concerned with matters of life and death. (Even his happier songs carry the weight of being saved.) Rather than express any of this urgently, McCombs meanders his tense and commanding electric folk-rock. My favorite ending to any song might be found in McCombs's "Love Thine Enemy," a song about embracing your role as a villain in someone's story and how there's no point in trying to be loved by all. You can hear McCombs throwing crumpled-up ideas into the waste bin and starting again, as the song tries on a variety of concluding measures and musical styles. Footsteps pace, tapes are shuffled around, a piano clunks, and vocals pirouette at varying volumes. Tonight, McCombs opens for John Cale. If you're not familiar with Cale's solo work (you really ought to listen to masterpieces like Paris 1919 and Fear right now), he's had a hand in some of the most important gateway albums to achieving good musical taste, as a founding member of the Velvet Underground, and as producer of Patti Smith's Horses and self-titled debuts like The Stooges and The Modern Lovers. Showbox at the Market, 7 pm, $29.50 adv/$35 DOS.