Looking for a departure from your average big-ticket charity fashion show? The fifth annual Rock City Music & Style Show, happening on March 20 at Harpers Ferry (158 Brighton Avenue, Allston, 617.254.9743), puts an edgy spin on fashion. (And isn't the neighborhood the kind of street-smart place where many trends originate?) Between sets by local bands such as Bad Ash, Pulp45, Monolith, Vagiant, and Superpower, organizers will send down the runway looks from area retailers including LAB Boston and Ritual Arts. "Burly men" will also strut their stuff with housewares and other gear from Model Hardware, New England Comics, and the Pet Shop. Doors open at 8 p.m. and tickets are $10; proceeds from the show benefit Allston Village Main Streets, a group that's working to revitalize the area's commercial district.