This is a neat one. Many scientific instruments have a complicated setup to move liquid through tangled channels. After all, your house has all these pipes to move water around, most instruments are like that on a small scale. The trick is how to push the water around those complicated paths in the way you choose, on such a small scale. So far the most useful solution has been to make the "floor" of the pipes with rubber and run little air hoses up to the floor, and when you want to close off a pipe, you send air pressure down that hose. It works OK but has it limitations, especially because it's hard to make an instrument smaller than, say, a washing machine with this setup.
So, what if instead of air, you could use music? The idea is to use different tones to move the droplets around the pipes. Say, pipe 1 responds to C natural, pipe 2 responds to E and pipe 3 responds to G. Play a G and the drop will move in pipe 3 only. It's not clear yet to me, but I think you may be able to use chords too. The cool thing about chords is you can superimpose notes and send them across the whole setup, and transmit complicated information that way.
This may allow many scientific instruments to be as small as a handheld, like a Star Trek tricorder. An iPhone that you sneeze into, it moves the drops around and analyzes them to tell you if you have the flu. And they will literally run on music. No word on if the iTunes software will be required.
Click here for a press release with a video of drops of water moving around to the U of Michigan fight song.