So, it looks like Meg White was playing a set of Chromatic Desk Bells, mounted on a big bit of wood. At just $77 for an octave (13 notes, two Cs), I imagine these things must make a pretty impressive racket. If you're feeling superfly, go for the $120 20 note set. Props also to the anonymous poster who suggested she was playing a Bonang, an enormous Javanese instrument which does look a bit similar.