Is it possible to impend frequency with reverse bias on objects to destroy or create with other frequencys?

If something emits natural frequencies and has different properties of the force being emitted through it. Example: metal can be moved over a crystal to find a frequency. when voltage moves through metal it travels along frequencies. but if a capacitor is moving voltage through metal back to itself how is it that the metal that has different frequency to emit the frequency of the voltage instead of it being moving through it. im not asking about the voltage in terms of its frequency. So if i had a crystal and moved metal across it while the metal wouldnt emit the same frequency it would as the voltage, it would be much like trying to see voltage of a different kind go through metal other than the natural frequency of the metal that conducts the voltage?something specific im trying to say. is metal emitting voltage that doesnt go through it like reverse bias "reversed" where as a crystal does the opposite because of reverse bias... saying it allows the frequencies to go through it? could it be that electricity is a ground for something else or a ground is for electricity as reverse bias is to different frequencies. I need information i guess.