This is a tough one :)
When I listen to this amazing track (track 14 from "That was then, This is now" album) I notice at 0:36 and 0:42 a very fast vibration on the G string (5th fret) which I doubt is possible using your fingers. I was wondering how exactly does he achieve this sound (its like a very fast and short vibration/trilling sound).
When I pull/release the tremolo bar (fast) it sounds like it but I was wondering how exactly he does it.
thx