I've noticed that my instruments that don't get played very often have a thin layer of dust on their headstocks. The ones played often don't have any dust on them. The thing is, I haven't dusted these off. What could be keeping the headstocks clean? My theory is that vibrations from being played are keeping the dust particles from being able to hang on. What do you think? Also, has anyone noticed wether a thin layer of dust affects tonal qualities. If so, does it have a positive or a negative effect on the tone?