Part historian, part reporter, part sociologist, Sandhu speaks as quickly as he walks and dispenses a torrent of observations and information. We walk by the hospital that treated the Elephant Man; pass the work of a graffiti artist sought by Wired magazine and the New York Times; stroll through the courtyard of the Friends of Yiddish, the world's oldest reading group (way before Oprah's, says Sandhu), which once boasted 2,000 members and includes eight members today; and visit the former storefront of a Mr. Katz, who supposedly sold 298 different varieties of string until he died in the late 1990s. "No one ever bought anything, but he was there every day at 8:30 a.m.," Sandhu says.

Whatever his eyes light upon - the building, the sign, the spray-painted art - prompts a story or a reference to a book, a movie, or a historical fact. Sandhu mourns the loss of a building or a landmark as if it were a family member. Like Gene Kelly in that famous scene from Singin' in the Rain (minus the yellow slicker and the downpour), he zigzags through the streets, which seem to energize him as he bustles from one touchstone to the next. "I'm not interested in nightclubs or the buzzing 24/7 city that city boosters are always raving about," he says. "I want to uncover different, more scuffed textures; lower rhythms; dowdier individuals. The buildings and streets that I grew up with are disappearing fast. My project is, in its small way, a kind of salvage operation, trying to spotlight and honor the people who create this city's infrastructure and make all the fun possible."