There is a tight cluster of blocks filled with post-industrial buildings in North Chinatown, sandwiched between Spring Garden Street and the old railroad viaduct that will soon be developed into an elevated green space.

Developer Craig Grossman calls it the Spring Arts District. His company, Arts + Crafts Holdings, has been snapping up buildings there.

"This is a pocket that has been passed over. Time to show it some love," said Grossman. "If we fill this in, we knit together Northern Liberties, Fairmount, and North Broad with Center City."

"It's like filling a hole in the doughnut," he said.

Grossman is partnering with the Mural Arts Program to bring some color to the drab brick and concrete streets. Six walls will be painted by six artists; in a year they will be painted over by a new set of artists, and so on.

Right now, there are two completed murals, one at 10th and Buttonwood by Matt Moore, and another around the corner on Ridge Avenue by Kid Hazo. Four more murals are forthcoming next month around the same block.

The Mural Arts Program has never before established a regularly changing collection of murals. It allows MAP and the artists it hires to play it fast and loose. Mural Arts will not be giving these murals the same resources it normally gives permanent murals, which sometimes require extensive preparation of the wall.

"We're not going to take a chance on a surface that is precarious," said MAP director Jane Golden. "We used to, a long time ago: 'Let's just do it!' Now our director of operations would say — which she does on a weekly basis — 'No, Jane, we can't do that.' Here, it allows us to be experimental. To embrace risk, but smart risk."

Golden said the more nimble selection process allows her to work with a wider range of artists. Right now, the Mural Arts Program hires about 200 artists a year.