Hi everyone, first time post here. I know (or at least think I know) that strings can sympathetically resonate at harmonic intervals. For example, a string whose fundamental is 400Hz is able to resonate at 800Hz if it's excited by a 800Hz source. Maybe I'm wrong on that as well? heh.. Anyways, what I'm wondering is if being able to resonate at harmonic frequencies is something that is just reserved for strings? Can a solid steel wire do the same, or can an xylophone key for that matter?