With the power of a full-tilt rock concert, Foreigner came to town Saturday night and shook the foundation of Staples High School's field house -- a rip-roaring rockin' start to the 40th season of the Levitt Pavilion for the Performing Arts.

"I see you all sitting there so nice and polite," lead singer Kelly Hansen told the crowd of 1,800 seated in row upon row of chairs facing the enormous stage assembled on the northwest side of the field house. "This isn't a high school graduation. This is a rock concert!"

Following two of the group's many hits spanning four decades --"Double Vision" and "Cold as Ice" -- the crowd made it standing room only by flooding the floor in front of the stage. "Are you guys read to have a party?" Hansen yelled. "Let's get this thing started!"

This concert, which was the main fundraiser for the Levitt, which on Tuesday was scheduled to open its summer season of more than 50 free performances, was preceded by an acoustic show by the band for VIP ticket holders behind the barn at the Wakeman Town Farm.

For many of the fans 40 years old and over at the two Westport events, Foreigner's string of hits was a celebratory blast of rock 'n' roll from an iconic band.

"They probably have 30 amazing songs," said fan Steve Messina of Darien. Growing up in Westport, he said, "I listened to their albums over and over again."

"Those years, those hours, they were really great," he said. "It's a thrill to have them here."

Formed in 1976 with British and American musicians, Foreigner has recorded 10 multi-platinum albums, along with 16 top-30 hits. While the band has performed in a variety of incarnations, guitarist and songwriter Mick Jones remains the only member from the original group.

"I'm incredibly impressed with how great they sound," said Joe Troy of Westport. "I'm incredibly impressed with how great they look."

The front four members of the group began the evening playing three songs for about 100 people at the farm, after which they took photos with fans.

"They still have it," said a woman named Mary, who drove down from Boston to attend the show. "Their singing is wonderful, their playing is fabulous, and it brings back a lot of good memories."

"They're very entertaining and they're very charming," she said.

"Unfortunately we can't do a full thing out here for you," Hansen told the small crowd after their first set at the farm, "because we've got this other thing we have to do."

"In a big, sweaty gym," said bassist Jeff Pilson.

"I'm 57 years old and every song that they sing, I remember," said John Seigenthaler of Weston. "They're a terrific band and a very talented group of people."

"We're very excited to have Foreigner here in Westport," said Janet Plotkin, the chairwoman of the Levitt's governing committee.

The Levitt is still raising money for its new home on the banks of the Saugatuck River, with plans to begin construction on the complex this summer. To make way for the work, the Levitt's free shows will be staged on Jesup Green.

The new pavilion, Plotkin said, will be something "the town is really going to point to with pride."

"We want people to support the Levitt," she added. "We still have to raise a lot of money and we want the community to be part of it." The projected cost of the new Levitt is more than $6 million.

Freda Welsh, the Levitt's executive director, said the kick-off concert with Foreigner was geared to help meet the $500,000 operating budget for the summer season, which includes more than 50 free shows.

"All of our performers are paid," she said, "so we depend on this annual event."

"They seem to come through for us every year," she said.