Ascending the steep sidewalk in front of the Kennedy Center last night, through a chilly wind, was George Caddy, 46, of Alexandria, in a motorized wheelchair, and his wife Judy. They were heading to last night's annual sing-along of selections from Handel's "Messiah."

"We come every year," said 38-year-old Judy Caddy, two copies of the "Messiah" score in one hand as she pushed the wheelchair with the other. "This is the seventh or eighth time we've been. We've been every time except for two years when we were out of town. My son usually comes but he had to work tonight."

Inside there were thousands: the lucky ticketholders in an excited but well-behaved swirl around the steps of the Concert Hall; the unluckier ones waiting for no-shows in a line six deep that wound from the cluster and all the way down the Hall of Nations. One group was singing "Greensleeves" to a solo kazoo accompaniment.

When the the tickets were given out two weeks ago, people lined up at 4 a.m., hours before the box office opened, according to a Kennedy Center spokeswoman (take that, Prince). But last night's cold weather ensured enough cancellations to get everybody in. And the crowd was as excited as it was varied -- old and young, families and singles.

"How many people were here last year?" asked Paul Hill, who has led the show with his Paul Hill Chorale for the last 13 years. More than half the assembled raised their hands. The evening belonged to Hill, as he playfully chided the audience when it wasn't singing up to par. ("First of all, your entrance didn't pop like it should. It just sort of sponged," he said to laughter at one point.)

Although the enthusiasm was there as usual, there weren't as many tenors, Hill said. However, "the general tonal quality was good," and the "audience's response to the musicians was wonderful," he added.

This year marked the first time the sing-along featured conductors and soloists from the armed forces. Particularly noteworthy were Air Force Tech. Sgt. Daisy Jackson, a delicate and pleasing soprano, and Master Sgt. Donald Frank, an accomplished bass-baritone.

Naturally the climax of the evening was the concluding "Hallelujah" chorus, led in traditional fashion by the Washington Opera's general director, Martin Feinstein. The audience cheered so loudly at the end that Feinstein had everyone sing it again.

But why does "Messiah" pack them in every year?

"My mother loves the "Messiah," said 21-year-old Ed Maguire of Cleveland Park, a music major at Columbia University. "She's part of a singing group -- they're all amateur singers -- and this gives them a real thrill to sing along with one of their favorite works."

"The universality of this music isn't equaled by any other," said Hill.

"Who can't be inspired by this?" said Joe Dunne, 63, a topographer from San Francisco, his arm around his little granddaughter Joanne, whom he was visiting. "I went to the San Francisco sing-along and I heard about this. I wouldn't miss it for the world." Thinking about it again, he said, "It's being with the multitude of angels. Almost."