Is it possible to vibrate a string with electricity? I'm guessing an electro-magnet placed close to the string would be able to vibrate it. If the electro-magnet is used to vibrate the string, I'm guessing the electro-magnet should be pulsed at the fundamental resonate frequency of the string? Maybe different frequencies or harmonic intervals are more efficient? And I wonder should the electro-magnet be fed a sine-wave or is some other wave more appropriate to excite the string? Also is there anything that would tell me where the most efficient placement of the electro-magnet would be?