Behind the drums, stage right, there appears to be a marimba or a xylophone. The tube like resonators are clearly visible. This means that Stew will have a percussion setup behind the drums - like the Synchronicity tour, or more recently, the Oysterhead tour. What songs had the xylo? King of Pain. Any others? Footsteps maybe?
Unless they are playing King of Pain at the Grammies, this setup appears to be for a rehearsal for a tour; not just one song.