Hundreds of Cambridge residents descended outside City Hall Friday night for the city’s annual Dance Party.

Started in 1996 as part of the festivities for Cambridge’s 150th anniversary, the night allowed both participants and onlookers to have a colorful, musical evening.

Though the dance was scheduled to start at 7 p.m., few Cambridge residents had arrived at that time. A lone dancer, George T. Stylianopoulos, took to the streets in an orange shirt, encouraging others to dance.

"I start early. I’m a little impatient," said Stylianopoulos as he urged onlookers to join.

He didn’t have to wait long. Soon enough, a woman in a turquoise trench coat joined him for a quick box step.

Songs like "Hound Dog," "Dancing in the Street," and "Don’t Go Breaking My Heart" blasted through Central Square, while an orange and red light show lit up City Hall and the block closed off for dancing.

Katie M. Richards, who grew up in Cambridge, brought her young son Max D. Montpeller along for the festivities. Montpeller entertained onlookers with his smooth moves, despite never having taken dance classes.

"We love it. It’s the beginning-of-summer event," Richards said.

Joined by her husband, longtime Cambridge resident Kathleen M. Lesley said she enjoyed seeing the street closed down and the multitude of children who came out.

"I can't dance at all," Lesley said, but even she and her husband Don M. Lesley consented to dance with the large crowd that had gathered by that time.

By 8 p.m., the dance had swelled to over 200 people. Some middle-school students videotaped the dancers from the sidelines, while families with young children circled around three young men entertaining the crowd with their break dancing skills.

"It’s a great event. It’s a great energy," Richards said.

—Staff writer Leanna B. Ehrlich can be reached at lehrlich@college.harvard.edu.