I forget to say, that sometimes, when you strike a note and let it hang for big sustain, or if you do a long trill on the same string, try muting with your picking hand! Not the common palm-mute, just use the fingers not holding the pick, and touch the string above and beneath the string you're playing.
This works indeed if you want to control a feedback of just a single note!
Work that ****in' guitar!!!
Fiddles
Trolle
