Sorry to revive an old thread but after reading An American Demon I can now confirm a tie for toughest musician.
It's a toss up between TSOL's Jack Grisham who stole from beat up and violated more people than anyone can remember and Circle One's John Macias who more or less did the same and took five bullets from the LAPD before he went down. Grisham may have an edge, being a borderline psychopath and possibly having killed someone and kicked a biker's eye out with a spur.