Ever wonder what’s happened to all those old telephone booths? Well, Studio Place Arts in Barre has repurposed one of them — sans phone — as a very tiny art venue. Named the “Quick Change Gallery” (presumably a reference to Clark Kent/Superman’s speedy switcheroo?), it’s clearly suitable for exhibitions of small works. Currently, that would be a dozen pencil drawings by Mark Heitzman. The central Vermont cardiologist and artist is noted for his minimalist but meticulous works; his phone booth show, titled simply “Graphite,” is no exception.