Although it was well-timed to ride the wave of Johnny Cash nostalgia that hit a fever pitch with the 2005 biopic Walk The Line, Ring of Fire flopped on Broadway. Still, Cash fans could do a lot worse than this touring jukebox musical, which the Milwaukee Theatre hosts today at 2 and 8 p.m. It wisely resists the temptation to anoint a single Cash surrogate and instead takes an ensemble approach to his songbook. The musical is short on plot but heavy on music: Over 30 songs are included, ranging from Cash's early staples to his final hit, a cover of Nine Inch Nails' "Hurt."