First off about the only thing I really know about electronics is Ohm's Law. I was sick as hell yesterday, fever dreams and the whole bit, people who go out in public when sick with stuff like that should be publicly flogged. But in one of those dreams I watched myself wrapping the inside of a steel sewing machine bobbin electrical tape, then filling it with very fine wire using the sewing machine's bobbin winder, painting the windings in epoxy cement, then sticking a steel 1/4 inch flathead screw through a countersunk hole in the soundboard of a guitar, shoving the wire wound bobbin on it, then a very strong ring magnet the same diameter as the outside of the bobbin and securing the works in place with a couple lock nuts, and put one under each string in a diagonal row, all wired together in parallel. My question is would it work, or is it no more real than the faces that were showing up all over the place in the wood grain when I wasn't asleep? The ring magnet should magnetize the steel parts by contact, so the windings would be in a magnetic field. If you don't know, and if I can find a magnet like that I might have to try it. But just make one and test it first, copper is too expensive.