It was the perfect catch for a Labor Day weekend in the city.

Hundreds of brightly colored Frisbees crisscrossed the Mall between Third and Fourth streets, looking from a distance like motorized confetti. Spectators lounged on towels. Music pounded from loudspeakers.

With a little imagination, and without the Capitol and the Air and Space Museum as backdrops, it could have been a scene from Ocean City, Md. But about 10,000 persons passed up sand and surf yesterday for the grass and gravel of the Mall to ooh, ahh and ogle the performers at the 8th Annual National Frisbee Festival.

"The reason it's popular is because it's a family event," said festival director Larry Schindel.

Some performers cited a more mystical attraction. "A ball does just one thing -- a parabola," said Jack Roddick, the 1984 World Senior Grand Master Frisbee champion. "But a Frisbee is part of you and part of the air that you throw it in."

Whatever the reason, families showed up in force with children and canines, feeding their kids from picnic coolers and refreshing their dogs with upside-down Frisbees filled with water. Two of the most popular participants were Scotland, a male porter collie, and McTabish, his father. The dogs chased Frisbees with high style, leaping in swift arcs to snatch the discs from the air, dashing up behind their kneeling owner to grab Frisbees from her outstretched hand.

Jendi Holmes, 19, said the hardest part of training her dogs was teaching them to retrieve the Frisbees. She said she started by training McTabish to catch a tennis ball. "But first I had to tie a rope to it -- he used to just grab it and run away."

Jens and Erwin Velasquez, from North Plainfield, N.J., have been playing Frisbee together for about 10 years, Erwin Velasquez said. They specialize in free-style play, a loosely choreographed duet of fancy throws, spins, dance and acrobatics set to music.

"In order to do it, you need a partner. . . . We're a little different, but when we're out there together, we're one. We complement each other. We're brothers and we play Frisbee with each other all the time," Erwin Valasquez said.

Three hour-long shows demonstrated the finest and fanciest in Frisbee technique. Performers showed off the traditional catch-it-behind-the-back, throw-it-between-the-legs maneuvers and some newer, more subtle moves such as tipping, or bouncing a spinning Frisbee off one finger tip.

There was air-brushing -- racing across the Mall behind a flying Frisbee, keeping it aloft with swift taps to the side of the disc. And there was body-rolling, performers turn into human roller coasters, wriggling and twisting to make the discs roll on edge across their backs, over their necks, up and down their arms.

Some of the performers have been playing long enough to remember when these tricks were on the Frisbee frontier. "Originally, free style was all fancy catches and that was it," said Roddick, 62, of Shippensburg, Pa. "Then somebody found you could tip the Frisbee, maintaining the spin of the disc and delaying its death. There's no longer much of the behind-the-back stuff. This other's just taken its place."

There was room yesterday for the basics, too, in workshops that gave spectators a chance to spruce up their Frisbee skills.

Peter Hickey, clad in the dark blue shorts and powder blue T-shirt of the festival staff, grinned at his prodigy, 3-year-old Katherine Massey of Alexandria.

Katherine tugged the tail of her red shirt neatly over her shorts and sent a blue Frisbee sailing straight into Hickey's hands.

"She can throw a two-finger forehand. That's hard to do," he said.

Katherine's father, Jerry, watched her jump and twist to the sound of "Footloose" pulsing from the loudspeakers, then looked across to the Mall, where Frisbees zigzagged over the grass, flying in the smooth arcs of experts and the wobbly paths of beginners. "This is American, isn't it?" he said.