The black nylon shirt thing is one of life's mysteries along with the "how on earth does Wilko appear to be playing rhythm guitar but sound like a rhythm guitarist and a lead guitarist at the same time (and what's that autistic across and back the stage thing he does all about?)?" question.  I'm not a guitarist, maybe the answer is obvious to a guitarist (the rhythm/lead part of the question, not the silly walk part)

Gig acoustics.  Mostly awful true, but some real standouts and when its good its truly awesome.  Rescue Rooms are actually very good for this, ditto Jazz Cafe (we saw Roger McGuinn there a few years back and I spent the evening completely slack jawed).  Rock City truly stinks though.  Like listening to one of those awful subwoofered up cruise mobiles from the outside.