Using a britta jug and a makeymakey controller I'd found at Goodwill, as well as phone cables from old phones that I had laying around, I made a water based MIDI controller instrument. With a grounding wire at the bottom, the height of the water (as well as sloshing it) would ground different conductors, sending a voltage difference signal that would read as keyboard inputs. This would then be decoded by a MAXMSP patch to create music.