When Market Square was renovated in 2010, permanent public art was not part of the plan. The plaza is a transitory place, a hub of movement, a sort of public dance that inspires people-watching.
That quality inspired Jeremy Waldrup, president of the Pittsburgh Downtown Partnership, and Renee Piechocki, director of the Office of Public Art for the Greater Pittsburgh Arts Council, to drum up an idea for public art with transitions.
"Congregation," the debut installation of the Market Square Public Art Program, was the perfect fit, Ms. Piechocki said.
It opened Friday night and plays through March 16. The Market Square installation also is the American premiere of the work.
After dusk every evening -- until 10 p.m. during the week and midnight on weekends -- the light and sound installation will run in 25-minute loops, each one different as human activity choreographs the piece.
"Congregation" was created by British artists Kit Monkman and Tom Wexler, who produce as KMA. Commissioned here with $75,000 in foundation money, the work debuted at the Shanghai Expo in China in 2010.
The artists will give a public talk at 3:30 p.m. today at Point Park University's GRW Theatre, 414 Wood St. A public reception will be held at 6:30 p.m. at the Original Oyster House in the Square.
A crane in the square's northwest corner holds the boom lift, which holds a camera that projects a light video onto the plaza. A heat sensor camera detects people moving through the light. Another camera projects the plaza scene onto a 50-foot screen.
During a recent test run, at exactly 8 p.m., light sprinkled onto the plaza like pixie dust. The artists were first to the dance floor, roaming through the light with their arms outstretched. People began to appear and wandered toward the light. A trio of friends held hands and made a circle of light appear. One woman lay on the ground and a ray of light zipped around her form. Two young brothers walked gingerly inside a beach ball-sized light circle and made it morph by stepping away from each other.
"The most exciting thing is when someone walks across and starts playing with strangers," Mr. Wexler said.
As their sons played in the lights, Tim and Nacole Benson, visiting from Bemus Point, N.Y., commented on the experience.
"We were just talking about the fountains in Toronto," he said.
"This is that kind of a draw," Ms. Benson said. "We can be in Toronto in 2 ½ hours or in Pittsburgh in 2 ½ hours."
Market Square was renovated to be a more vibrant hub with an enlivened restaurant scene and cultural programming. The $5 million result: More than 25 new restaurants in and around the square, triple the patrons to the weekly farmers market and more than 150,000 shoppers at the Holiday Market, Mr. Waldrup said.
"Temporary public art was always considered a component of effective programming," he said. "One of the things I noticed when I first moved here was that when winter comes, nothing really happens in Market Square except a St. Patrick's Day event. It is such a great public space we thought we should" come up with a large-scale attraction.
For three successive winters, the public art program will commission a work for Market Square. A city ordinance created the program in a collaboration with the Pittsburgh Downtown Partnership and the Greater Pittsburgh Arts Council's Office of Public Art.
About 130 artists and artist teams worldwide responded to a call for submissions last year, when "Congregation" was chosen, Mr. Waldrup said. Portland-based composer Peter Broderick wrote the score of "Congregation."
Diana Nelson Jones: email@example.com or 412-263-1626. Read her blog City Walkabout at www.post-gazette.com/citywalk.