i'm going to look into this stuff but
1. can you or someone be a little bit clearer? i've never done something like this before and
2. i can't help but think you're pulling my leg with this "licking my fingers" business
but I appreciate your input nonetheless!
1. Well, basically you can remove a resistor which controls pitch, and solder in a variable resistor (also called pot/potentiometer) which is controllable.
2. Nope, wet fingers can short the resistor slightly, lowering/raising the value of it. That way (by listening) you can isolate which resistor is the pitch resistor.
If the keyboard uses a crystal clock/oscillator for pitch, making a circuit might be a tad too complicated to attempt at the moment.
EDIT:
Googling the keyboard, it looks rather new (and therefore quite complicated) so it will probably use an oscillator to control pitch
I'm not sure how the keyboard would do with other bends, if you try shorting the chips (the pins which connect to other chips) inside you might be able to glitch it.