Celebrate Fairfax!, Northern Virginia's largest community-wide festival, attracts tens of thousands of visitors. Some come for the carnival-style rides and children's activities, others like to explore the science and technology center and community group booths, some like to shop for crafts and other merchandise.

Live!, of course, loves it for the music. Once you've paid your admission fee, the performances are free, and there are six stages with entertainment, running the gamut from local groups to regional bands to national touring acts.

That's a lot of music for your money.

The headliners this year include Vertical Horizon at 8 p.m. tomorrow, a muscular pop-rock band that hit the big time with its 1999 album, "Everything You Want." The CD's title track is a modern adult-contemporary classic that still gets a lot of airplay, and two more singles from that album, "You're a God" and "Best I Ever Had," proved that Vertical Horizon was no one-hit wonder. The band, which traces its roots to a Georgetown University undergrad party, has toured with the Dave Matthews Band and Barenaked Ladies and is now on the road in support of its 2003 CD, "Go."

It seems only natural in an election year that the Presidents of the United States of America return to the D.C. area (they played at last year's Celebrate Fairfax!) to campaign for your musical vote at 3 p.m. Saturday. An engaging group of goofballs with serious rock chops, POTUSA turn every show into a good-time rally with hits such as "Lump" and "Peaches."

The Pat McGee Band, which plays at 7 p.m. Saturday, is a Richmond-based regional favorite that just released its fifth CD, "Save Me," on Warner Bros. The band has opened for big names, including the Allman Brothers Band and Blues Traveler, but the group often headlines, too, having built up a devoted fan base along the East Coast.

The Charlie Daniels Band, which plays at 4 p.m. Sunday, will wrap up the Main Stage events with a rousing set that, one hopes, will include the breakout hit, "The Devil Went Down to Georgia" which bridged the country and pop charts in 1979.

Latino performances are featured Sunday on the smaller stage located in the food court area. At 11:30 a.m., Los Quetzales Mexican Dance Ensemble blends music, choreography and Mexican folk dance traditions. At 12:45 p.m., El Tayrona Colombian Folklore Music and Dance explores the rhythms of Spanish, Italian and African cultures, using hand-made costumes and props. Mariachi Las Estrellas, which plays at 2 p.m., combines violin, trumpets and more exotic instrumentation like the guitarron and the vihuela to capture the spirit of traditional mariachi.

The Nicki Gonzalez Band follows at 3:15 p.m., spotlighting the brother-and-sister team of Nicki and Ira Gonzalez, area musicians whose original music combines jazz, R&B and pop.

Patrick Alban & Noche Latina create sensual Latin acoustic rock at 4:30 p.m., with accents from the salsa, samba, tango, bolero and blues traditions.