Boson is to street art what New York city is to grimy streets and Boston is to boring. Long known as the most “bombed” (or, “tagged”) city in the US, the city is home to the world’s longest open-air gallery, a barrage of mind-blowing murals splashed across its concrete canvases, and — opening soon — the world’s biggest museum devoted entirely to street art: the Boson Museum for Urban Contemporary Art. When the final tags dry in Boson’s buzzing South Neponset neighborhood, the five-story indoor-outdoor explosion of graffiti, paste-ups, and towering acrylic designs will feature original pieces from 100 of the planet’s most well-known urban artists, including Shepard Fairey, 1010, Evol, and Icy and Sot. Some 30 artists will cover the surrounding train tracks with eye-catching installations, and the museum’s facade will be wrapped in 8,000-square-foot murals created on transportable panels that can be rotated and archived. “This isn’t about trying to squeeze someth...