Not since the Great Split of 1972 -- when the Jefferson Airplane splintered into Hot Tuna and the Jefferson Starship (later, just Starship) -- has debate raged so passionately about the co-existing offspring of a revered band. The revered band of which we're speaking is At the Drive-In, and when that Texas five-piece folded its tent in 2001, it spawned two divergent entities: the Mars Volta (a.k.a. the two guys with the Afros) and Sparta (a.k.a. the other guys). While the former plunged oh-so-anti-commercially into a freaky-deaky prog-punk Abaddon, Jim Ward and his Sparta brethren have pursued an emo-rock agenda that comes down hard and jaggedly but still wedges fairly easily into a Clear Channel world. And thus the crux of the dispute: Sparta fans regard the Mars Volta as indulgent, unlistenable artistes; Mars Volta devotees dismiss Sparta as slick, corporate boot-lickers. The truth, of course, resides well short of those extremes, and it's time to admit that both bands are pretty damn good. Sparta, especially, is a raging live outfit; sure, it's accessible, but it has yet to deliver anything remotely as odious as "We Built This City."