Billy Joel and Elton John's face-to-face, dueling-piano tour makes so much sense, it's amazing that someone didn't think of it sooner. In the past fifteen years, the pair has refined the content of these occasional tours, playing individual sets, squaring off to play each other's songs and throwing in hits from the early days of rock & roll. The men are opposite sides of the same coin, separated only by nationality: Both began their careers writing overly long, somewhat abstract rock songs before refining their style into equal parts soft-touch balladry, pristine pop and anthemic fist-shakers prior to fading into irrelevance by the '90s. No matter, though — by now, Elton and Billy's cultural cachet is so deeply ingrained in our collective subconscious that nothing short of a lobotomy could remove their stamp on pop music. You either hate them or love them, and if you love them — well, you probably already have tickets to this show.