The five nine-foot horns that stand in front of the Hyattsville Justice Center are meant to echo the community. They are colorful and dynamic -- and they make noise.

They also make up "The Hyattsville Horn Section," one of two county public art projects formally dedicated last week.

Created by Massachusetts artist Christopher Janney, the work is constructed of five independent parts made to look like wind instruments. Each horn bears a map of Prince George's County painted in vibrant colors, as well as silver musical notes.

Each horn also has a plate with a hand painted in the middle, urging passersby to touch it. Doing so will trigger a series of sounds that signify aspects of the county, including the noise of gunshots in historical battles, narrated text about county history and the sounds of bluebirds, crickets, kids on a merry-go-round and college students chanting "Go Terps."

Janney, 50, calls his work a "sonic portrait" designed to be ever-changing, so that a person who walks by the sculpture at the same time every day and touches the horns in the same pattern will never hear the same sequence.

"It's living in the community. I don't want it to become monotonous or repetitive," Janney said. Trained as both a musician and an architect, he has been constructing public art based on the intersection of the two disciplines for 30 years. Since 1978, the native Washingtonian has been working on his series of urban musical instruments.

"I like to make things that are elegant but accessible. . . . If you think of all music being made up with rhythm, harmony and melody, I give the rhythmic part of the piece to the public. How they touch it and when they touch it is what triggers the music," he said.

To keep community members engaged with the sculpture, Janney has also installed a riddle on the ground in the middle of the horns. If people solve the riddle by touching the hand plates in a particular sequence, a jazz saxophone piece plays. Janney plans to change the riddle from time to time, with the help of the community, so that it reflects community changes.

Part of the reason Janney was chosen from a pool of 110 artists in 2002 was because his work best reflected the revitalization of the community through the Gateway Arts District, said Lauren Glover, director of the county's Art in Public Places program, which commissions art projects.

"The Hyattsville community wanted something that was really going to stand out as a beacon in their community and something that was inviting, since the government complex seems a little ominous," she said.

Another artist, Curtis G. Woody, was selected to create a 16-by-4-foot mural nearby, in the main lobby of the County Service Building, in recognition of the Department of Family Services.

Woody, who lives in Kettering, painted "Building and Sustaining Families," a series of silhouette forms of individuals and family units interacting atop a colorful background of textured, acrylic blocks.

"I've been living in Prince George's County for 30 years, and I've seen it change and seen it grow, and the arts are an important part of it," said Woody, 54. "I envision 10 years down the road a very large arts community where lots of people are coming into that district just for the arts," he said. "I'm pleased to be a part of it by having a permanent piece there."

"The Hyattsville Horn Section: An Urban Musical Instrument" is located in front of the Hyattsville Justice Center, at the corner of Baltimore Avenue and Farragut Street. "Building and Sustaining Families" is in the entryway of the County Service Building at the a same location. 301-883-7851.

Artist Christopher Janney, above left, talks with County Council member Peter A. Shapiro (D-Brentwood) in front of Janney's "The Hyattsville Horn Section," one of two public art projects dedicated in Hyattsville on Wednesday. At left, James A. Dula, the county's deputy chief administrative officer of health and human services, talks about "Building and Sustaining Families," a mural by Curtis G. Woody in the main lobby of the County Service Building.