Okay, it's a stretch. Despite its name, the Wetronome covered yesterday by Gizmodo
is intended for pacing strokes in swimming, not music. But given the
innovations in portable music covered here alone, why couldn't your
next instrument be — waterproof? The Wetronome is a model of aquatic
design, completely sealed and programmed with a magnetic wand. If your
cello weren't water soluble, you could be practicing in the waves right
now.

Don't let me down, technology inventors out there. I know you're up to the task.