The latest fashion accessory

Strolling into town this afternoon I came across a couple of little jazz ensembles, playing away. It then dawned on me that posters I'd seen advertising the Wall2Wall Jazz Festival might have something to do with it. And indeed it turns out it is on today and tomorrow. I'm no lover of jazz, except that I have a soft spot for the very old-fashioned sort, and a peculiar weakness for sousaphones. So how could I resist blipping one?