From Music Hack Day
A browser based drum machine with simple multitrack sequencing named and styled after the famous AKAI MPC2000. Drag and drop mp3 samples onto the pads, then trigger the pads with the mouse or keyboard to activate the sound.
 Use Cases
Boost fan engagement, e.g. by running a remix competition. Anyone with a computer could participate.
Also embeddable in iBooks author and iTunes LP as bonus content.