Saturday morning, the cellist wore a Hawaiian shirt. A first violinist was warming up in a warm-up jacket. A musical beehive buzzed on stage. Unannounced, a man walked on chewing a cigar, wearing a cowboy hat, brightly colored patchwork shirt, Adidas and jeans, and carrying a glass of water to the conductor. Before an audience of about 250, which in all filled about two rows, the National Symphony Orchestra was rehearsing at Wolf Trap for the evening's performance.

Watching them practice is just one of many free cultural events around town this summer -- along with free concerts and films, free poetry readings and Shakespeare performances. Free events this very Fourth of July are military bands playing at Wolf Trap all afternoon, starting at 2, and the Beach Boys at 4 on the Washington Monument grounds, and Sarah Caldwell leading the National Symphony at 8 on the Capitol's west lawn.

But when they're just rehearsing you have them more to yourself.

At the rehearsal, toddlers in the audience switched laps and parents sneaked food from coolers and music students stood sentry on one side of Filene Center, then the other, in search of the best acoustics.

That night, at the real performance, the orchestra would be in formal dress; the kids would be tucked in bed and there would be a different kind of magic. But now, during the rehearsal, the animal in the pianist was trying to get out. Andre Watts was the guest soloist, and clearly the piano is his outlet. There was such excitement on stage, his interchange with the orchestra almost palpable, that when they finished a Saint-Saens piano concerto, the orchestra members hugged or cradled their instruments to free their hands so they could applaud him.

A young man in the audience was reading Catch 22. Another man ten rows away was reading Good as Gold. Then Good as Gold joined Catch 22 in Row Q. They did not discuss Joseph Heller, but the pianist, whom they greatly admired. And after the rehearsal, Watts came out and answered questions from the audience, about his career and about things they'd noticed: why he hunched over the keys just so, whether he thought the piano was well tuned, and how he got along with the orchestra.

Mary Brown, who helps run the summer interpretive program for Wolf Trap, says, "Unless you are interested in music, you are not going to come to a rehearsal." That includes a lot of people, right there.