We've seen the iPad do some funky stuff so far in its short little lifetime, but we're going on record as saying we haven't seen anything as beautiful as this (although David Jon Kassan's Brushes portrait was stunning).
The Sweet Dream rendition is being played back using the Seline HD app (£5.49 in the App Store), which "features a completely new, ergonomically designed playing surface called ioGrid, suitable for players with all hand sizes.
"The melodies are played with two hands, while keeping the iPad on the knees or on the table. Fully adjustable 16-note scale is divided into 2 parts (odd and even), which are then mapped on the left and right grids. Such a way of note mapping is beneficial to the existing linear scale mapping solutions as it allows many more improvisation possibilities."
Basically, it's a clever iPad musical instrument and it's hard to argue that, when played by experts at least, it isn't pretty amazing.