Here's a guy on YouTube with an interesting idea -- run the tines between three rollers so the tuning can be easily changed:
Jamoflague has put magnetic humbucker pickups on the second one.
Interesting idea. I have two quibbles, though. He has to turn the knob with one hand while playing with the other --playing one-handed is a serious challenge. I would want the instrument to RETURN to its original tuning without my help. Both can be addressed by putting a whammy bar (tremolo arm, vibrato unit) on the knob and have a spring return. If the knob were a clock face, the the long hand whammy would stick out at about 3 o'clock, while a shorter hand would stick out at 9 o'clock with a spring attached. The whammy could be moved by the index fingers alone, while the thumbs would be free to play.