The rough drawing above is an image of a water based harmonica. Using a box full of impure water to conduct electricity. It is possible to suck water up to certain points of the straw to change volume and note based on which straw is being sucked on.
In addition, it is possible that using the caps lock feature (or 64 shift in ascii) from a button to change the “letter” or signal out put to something different. This may correspond to octave.
The corresponding animation may be an image of a ship in a bottle moving according the interactions of the “instrument”