Last year the two-day ADD (Activities for Downtown Development) Arts Festival attracted 15,000 spectators and more than 40 artists and performers. Next weekend, more than 50 musicans, artists, poets and crafts people plan to participate, and with a little cooperation from the weather, the crowds could be impressive.

"I can't believe the change {in Washington}," says Debi Smith of the folk duo the Smith Sisters. "I started out singing solo here and there was nothing." Now, she says, "Washington is a great town to perform in. The people always come out in droves."

Saxophone player Gary Thomas of the jazz group Seventh Quadrant agrees. Baltimore is his home, but he finds "Washington is much more hospitable" to the arts. "Washington has held a lot of opportunity for me and my band," he says. "The gigs keep coming in."

Smith and her sister Megan and Thomas will be part of the festival's all-musical Saturday at Western Plaza, 14th Street and Pennsylvania Avenue NW. The Smith Sisters kick off the evening's entertainment at 6 p.m., followed by the rhythm and blues of the Orioles, the Shirley Horn Trio, Thomas' Seventh Quadrant and a reggae band called Black Sheep.

From noon to midnight Sunday the festival moves to the area around the Gallery Place metro stop at Seventh and G streets NW. The main stage will host concerts and theater displays, while the Martin Luther King Jr. Library will run movies from noon until 6 p.m. Poetry is in the spotlight at d.c. space from noon to 6 p.m., followed by excerpts from the club's current cabarets "Dance Against Darkness" and "Man Without a Contra" at 7:30 p.m.

The visual arts are represented in the ADD festival, too. An exhibit at the newly renovated Stables Art Center (at 8th and D streets NW) will present art from members of the Takoma Park Arts Center. Would-be artists may make their marks on the Graffiti Wall at 9th and F streets, and children will be able to participate in a chalk-drawing contest scheduled for 1 p.m. at Vendors Alley.

Food and crafts will be sold but all events are free.

For more information about the ADD Arts festival, call District Curators at 783-0360.