It’s a fledgling movement, to be sure, but more and more rock bands are turning to the traditionally classical cello to bolster their sound, and add an unusual twist to a genre which has for decades relied on screeching guitars and hammering percussion. From indie-goth band Rasputina, which sports multiple cellos, to a Colorado-based acoustic rock quartet which recently decided that a full-time cellist could improve their sound, the cello seems to be overtaking the violin in the role of the classical instrument best suited to crossing over into the nightclub scene.