[DupleMeter]

Originally Posted by menhir

I was told by one of my guitar teachers that a well known late guitarist would casually rub his fingertips behind his ear to pick up some natural oil to reduce squeak.

I learned a similar trick from a well known jazz bassist. He would bring his left hand to his forehead, as if he were scratching his head. He was rubbing his fingers at the hairline to get some oils onto them.