Portishead: Hammerstein Ballroom/Deadmau5: Roseland, NYC

AT A LIVE MUSIC event, your eye naturally is drawn to what's happening onstage: guitarists thrashing and sawing at the air, vocalists preening between yawps, drummers keeping time with fills and kicks. But last week, two acts came to town that had audiences drawn to the action offstage; large video projections dominated the visual landscapes of both shows, and spaces normally thought of as mid-level venues were given an arena feel.