[Ania's] been working on extending a xylophone in a project called Multixylophoniomnibus. She’s fitted a piezo sensor on the bottom of each xylophone key, interfacing it with an Arduino. When a mallet hits a key the corresponding box augments the sound in one of several ways. It looks like she’s prototyped a box that twangs a rubber band, one that uses a solenoid to clap mini cymbals together, one that rattles a glass full of beads, another that vibrates a glass full of water, and yet another that rattles a chain.
It’s nice to see how versatile the xylophone is for instrument hacking. Her Flickr set is linked above but we’ve also embedded some prototyping videos after the break.