Everyone in Philadelphia has a favorite. It might be "Common Threads" by Meg Saligman, in which neighborhood youth appear to pop out of a stories-high mural to keep watch over the streets below. Or perhaps it's "Gimme Shelter," artist David Guinn's Morris Animal Refuge-inspired work featuring residents' pampered pets frolicking on an exterior wall. Mine is Josh Sarantitis and Kathryn Pannepacker's "Finding Home," a meditation on homelessness woven into a mural -- the piece depicts a tapestry assembled by the homeless themselves. 

These beloved works are part of the city's legendary Mural Arts Program, an ambitious project at the vanguard of public art. Thanks to their work, Philadelphia is home to over 3,500 murals large and small. 

"The Program has become uniquely Philadelphian," says Jane Golden, executive director of the Mural Arts Program. "Now we're often mentioned as the 'city of murals.'"

Once dominated by famous sculptors working on a grand scale, public art is increasingly interactive and integrated into the cityscape. A focus on "social practice," or engaging local communities in creating change through art, is borne out in pieces that are as thought-provoking as they are aesthetically pleasing.

"Public art works on many fronts at the same time," explains Golden. "It provides the environment with beauty, and is also a way of lifting up and transforming corridors. It can be a catalyst for community and economic development. Public art is often an emblem of a community or location, of the myriad voices that make up a city." 

"What we do can be of the same quality as what you find in museums, yet we combine public art with creative place-making and social practice," adds Seligman. "When you look at the impact of our murals, the multi-disciplinary way of these works and their take on serious issues, it's this kind of art that can crack the code when it comes to intractable stories."

Painting a post-industrial canvas

Across the state, Pittsburgh is experiencing its own public art renaissance. A growing public-private partnership featuring institutions such as the Pittsburgh International Airport and the city's Sports & Exhibition Authority is affording artists "a more varied infrastructure for public art," according to Renee Piechocki, director of Pittsburgh's Office of Public Art.

Notable works include the City of Asylum's "house publications," a series of rehabbed houses on Pittsburgh's Northside decorated with text by exiled artists-in-residence -- the goal being to someday encourage visitors to "read" their way down Sampsonia Way. Meanwhile, in the city's Homewood neighborhood at Love Front Porch, performance artist Vanessa German is encouraging kids to get together and make art in the name of healing one of the most violent corners of the city. 

Then there is Conflict Kitchen, a mobile installation where artist-chefs prepare the foods of countries with which the U.S. is in conflict, such as Afghanistan and Iran, as a way of bridging the global divide. Cuban cuisine is currently on the menu at the "Cocina del Conflicto," parked at one end of perpetually sun-drenched Schenley Plaza, steps from the city-center campus of the University of Pittsburgh. Students and nearby workers line up to place an order at the take-out window and wind up at a nearby table or on the expansive lawn -- but not before perusing a handout on the U.S.-Cuba conflict and hearing about upcoming events including the "Obama Speech," a crowd-sourced speech to be delivered by an Obama look-alike. Chef Robert Sayre, who oversees the food operation, spent 10 days in Cuba prior to this iteration of Conflict Kitchen.

"I was able to do a series of dinners in paladares, private homes that operate as a restaurant," says Sayre. "I met some of the most educated people I've met anywhere."

People-powered art in unexpected places

Public art is also morphing into a powerful tool for community engagement -- a way of connecting people to each other through physical places. 

"Public art's mission is to engage people in unexpected ways in unexpected places," says Kemi Ilesanmi, director of The Laundromat Project in New York City. "Instead of living in rarefied galleries, public art meets people where they happen to be and, in doing so, brings them something delightful, thought-provoking and engaging. It makes people take note of their surroundings in a different way, talk to one another and make a connection."

Ilesanmi recently took part in a panel on public art at the 2013 CEOs for Cities conference in Grand Rapids, Michigan. Back in New York, she's fostering the latest phase The Laundromat Project.

"Everyone has to do laundry, right?" says the artist with a laugh. "So, we decided to work with artists in a natural, organic meeting space. We've hosted a portrait studio, an indie film festival, even an oral history project. It's the element of surprise and unexpectedness that pulls you out of your routine and makes you stop and think."

Art as economic engine

Artist Tyree Guyton's ravaged Detroit neighborhood was once home to the likes of Wilson Pickett and Berry Gordy, now it hosts The Heidelberg Project, his large-scale plea for consideration. Guyton employs a handful of run-down homes as his megaphone, with one polka dot paint job providing a visual metaphor for diversity, while another house plastered with stuffed animals can be read as a plea for space in which kids can recreate. 

"Detroit is a canvas that was wiped clean," says Jenenne Whitfield, executive director of The Heidelberg Project. "No one had a plan after the auto industry's collapse, yet we've always been a creative city -- artists, musicians -- and able to compete. 'Placemaking' isn't a new term, it's just giving us wheels."

Those wheels are also generating revenue. According to a Williams College economic impact study, the project's $450,000 annual budget generated $3.2 million in revenue for Wayne County and an additional $2.7 million for the immediate community. 

"Just by its existence, people afraid to cross 8 Mile had to venture out to see this thing," says Whitfield. "They then explored other aspects of Detroit like the Motown Museum."

Hello, tradition? Meet innovation

In Minneapolis, public art has long been associated with sculpture, including Claes Oldenburg and Coosje van Bruggen's "Spoonbridge and Cherry" -- one very large spoon graced by a ripe red cherry serving as pleasing appetizer at the Minneapolis Sculpture Garden. 

"The Sculpture Garden is widely understood as a communal gathering place," says Eric Crosby, curator at the Walker Art Center, the Garden's home. "With the social and political aspects of our lives undergoing transformation, public art invites people to stop, think and create memories."

Case in point: Artist Fritz Haeg planted a circle of native, edible plants earlier this year as a demonstration garden for school groups and community gardeners. The artist felt it was important that people in Minneapolis come to the Sculpture Garden and find a bit of its wild history. On a more whimsical note, a collective of area artists worked on "Artist Designed Mini Golf," a 2013 installation alongside the Garden featuring 15 off-the-wall holes.

"The quality of iconic pieces in public art is not going anywhere," says Crosby. "However, it's a space that has to be constantly fed with more ephemeral, participatory and collaborative forms. It's how artists are working today."

Integrating the public into public art

The city of Cleveland has become a laboratory for public art under the guidance of LAND studio, a nonprofit engaged in public space design and development. 

"Public art is making places accessible by adding enhancements," says Megan Jones, marketing and communications director for the group. "We find that it's not just 'build it and they will come.' You have to activate a space, make it engaging and exciting."

In a new park in the Market Square section of Ohio City, the neighborhood-of-the-moment in Cleveland, LAND worked with an artist inspired by the nearby West Side Market. He crafted tables and benches that resemble fruit crates and created an "orchard ladder" that rests near a park gateway. 

Another example comes via the Edgewater Hill Blue Birds, achieved in partnership with the Detroit Shoreway neighborhood. In this case, the community wanted to use public art as a tool to expand neighborhood identity. The resulting casted bluebirds are sprinkled throughout the area, perched on utility poles, commercial buildings or even homes. While trees conceal some birds during the summer months, they are revealed in fall and winter, lending seasonal cheer.

"Many of the traditional industries that built Cleveland are largely gone," says Greg Peckham, managing director of LAND studio. "What remains, however, is a deep local culture that puts a high value on craftsmanship and hard work, invention and re-invention, and building a legacy for future generations."