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					Originally Posted by Undertoad  Yeah, but is there any physics reason why you need a big weight on the end of the neck in order to get resonance out of your body? | 
	
 There might be.
A while back I was browsing in a guitar shop and saw an accessory for electric guitarists, a heavy weight to clamp on to the head right at the end, with the claim that it would improve sustain and maintain the clarity of the tone over the whole length of the note.
I can imagine how this 
might work.  If the string is vibrating it will tend to pass its vibrations on to the head.  The head will begin vibrating, probably at a different frequency, thus creating interference with the string's vibration.  This interference would mess up the purity of the string's vibration and lead to shorter sustain.  Increasing the mass of the head 
might reduce this effect by keeping the head stable.
I did not buy one.  I have not tested it.  I am not a physicist.  I have not even googled it.  I just made this up.  But it sounds good... until someone shoots it down. :ducks for cover: