One could take the concept a whole lot further---for example,harpists could have little motors in place of those little levers that they have to reach up and tweak. They could be initiated by the use of foot-pedals,like those of an electric guitarist, or why not have a metal helmet on the harpist's head, with electrodes implanted in the brain ?? And five-string banjo players? WELL !!-----They could have servo-operated 'Scruggs Pegs' for those complicated breakdowns ! Hydraulics would be a better option than electrics,actually----a lot safer, for a start !! The string tension could be altered by miniaturised hydraulic swash-plate motors , although the noise of the diesel hydraulic rig might impinge somewhat on the performance. On second thoughts, I think I"ll stick to Mr. Grover, and his chums----It"s a bit tedious sometimes, but much more natural,somehow !!