JAMESTOWN—More than 2,000 singers and instrumentalists performed so well today in a musical salute to Jamestown’s 400th anniversary that even President George W. Bush joined in.

Following his short speech just after noon, Bush borrowed the conductor’s baton and waved it with abandon as a 400-piece orchestra anchored by the Norfolk-based Virginia Symphony blasted the “The Stars and Stripes Forever.”

It was a humorous and exciting moment during the first of two performances by a huge combined choir and orchestra made up of the 400-piece orchestra and a nearly-1,800-voice-choir that included the Virginia Symphony Chorus and regional and youth choirs from nearly every state.

Fifty members of the Virginia Symphony were joined by 350 10-to-15-year-old musicians from around the country, said the conductor JoAnn Falletta.

The original plan was to have precisely 400 instrumentalists, to honor the anniversary number, and 1,607 singers to reflect the year Jamestown was settled. The total would be 2007 to reflect this anniversary year.

But Robert Shoup, the Virginia Symphony’s chorus master, said the final number of chorus members who showed up was close to 1,800.

Caitlyn Yoshina, a 13-year-old member of the Hawaii Youth Opera Chorus, said the experience of singing in such a large group, and singing for the president, was thrilling.

“It was awesome,” she said just after the performance. “It was so much fun.”

The group of musicians was so large that singers sat in two large stands to the right and left of the tent-covered stage that held the orchestra, president and other dignitaries.

As Falletta conducted the orchestra, two choir conductors watched her on television screens and timed their conducting to match hers. Although there were brief moments when the chorus teetered on the edge of getting out of time with the orchestra, the performance mostly held together impressively.

Because of security requirements for the president’s visit, many of the musicians had to arrived by 5:30 a.m. so sound checks could be completed before 10 a.m. By mid-morning the singers, clad in long-sleeved blue T-shirts and clear rain ponchos, were shivering under drizzle that occasionally grew to driving rain.

But the rain stopped before noon, and the singers took off their ponchos before the performance began. The sun came out brightly during Bush’s speech.

By then the musicians had played the Olympic Fanfare and Theme, the National Anthem, America the Beautiful and a fanfare to introduce the president. They also played a very fast version of “Hail to the Chief” as Bush arrived.

Although Falletta later praised the president’s conducting, it appeared from the audience that his notion of the beat did not actually coincide with that of the musicians.

Shoup said being part of such a huge ensemble was a first for most of the participants.

“None of us have ever done anything like this before,” he said. “This pretty much stands on its own.”