Guitar Face: The act of making an unusual face while playing the guitar. The look typically resembles a look of pain, intense ecstasy, or sometimes even plain old gas.
Guitar face is a horribly disfiguring condition effecting tens of thousands of guitar players around the world.
Blues players (particularly electric blues players) seem to suffer the most horrendous effects.
The late Gary Moore was always good for a “face” or two… every time he played.