Twenty-two years ago a few jazz musicians got together in Northern Virginia for a jam session, humbly beginning the Manassas Jazz Festival. This year, the festival gathers legendary musicians Bill Davison, Kenny Davern, Tommy Gwaltney, Bob Havens, Art Hodes, Washington's own Van Perry and more than 30 others in a tribute to blues/jazz singer Maxine Sullivan, who died in April. Jazztimes are 8:30 Friday and 3 Sunday at the Washington Dulles Ramada Renaissance Hotel (Rte. 28 at McLearen Road), 12:30 and 8:30 Saturday at the Dulles Holiday Inn (1000 Sully Road). Tickets are $25 per show at the door. Call 631-1165. LOCAL FOLK MAKE GOOD

Looking for a down-home good time? "Full House" -- a concert by Mary Chapin Carpenter and the Saddle Sores, Grazz Matazz and Cathy Fink and Rhythm Ranch -- might be just the ticket. The joint concert, presented by the House of Musical Traditions, begins at 8 p.m. sharp Friday at Georgetown University's Gaston Hall (there's free on-campus parking at the end of Prospect Street for concertgoers). Admission is $12 at the door. Call 270-9090. WILD SHOWS

It's relaxing, but is it art? To some folks -- such as Penny Miller, a Virginia wildlife carver who has won more than 100 national and international awards -- woodcarving is serious. Miller's work and that of 60 other local and international artisans is part of the Northern Virginia Carvers show and sale 10 to 6 Saturday and Sunday at Marymount University (Glebe Road at Old Dominion Drive) in Arlington. It's $1; free for kids under 12. Call 532-1762 or 941-7064.

Also on the nature front, the Hashawha Environmental Center is having its first art show and sale noon to 6 Sunday at 300 John Owings Rd. in Westminster with paintings, drawings and a bonsai demonstration -- exhibiting the Oriental craft of miniaturizing nature, especially trees. Free. Call 301/848-9040. ANTICIPATION

Get a jump on Alexandria's big Christmas Walk (it's next weekend) with this Saturday's Scottish Preview at the Lyceum, 201 S. Washington St. All the family can enjoy Scottish dancing and bagpiping demonstrations, slide shows, fashion shows and more. It's free, 10:45 to 4. Call 838-4994. FA-LA-LA-LA FREDERICK

Frederick has decked its halls and decorated its fairgrounds for the Maryland Christmas Show 10 to 6 Friday, Saturday and Sunday. Six fairgrounds buildings will be open: Memory Hall, done up as a 19th-century village; four "craft villages"; and a holiday food emporium of baked goods, meats, candies and other goodies. It's $3.50, $1.75 for kids 12 and under. Take I-270 north to Rte. 85 (Market Street). Go north to South Street, turn right and follow the signs. Call 301/898-5466.

The rest of Frederick City celebrates the season with activities that include guided walking tours of the historic area at 1:30 Saturdays and Sundays (through December 27; they're $2.50), a Kris Kringle Procession at 7:30 Friday on East Patrick Street downtown, and the Schifferstadt Museum's holiday open house 10 to 4 Friday, Saturday and Sunday (1110 Rosemont Ave.). For details on any, call 301/663-8687. KITTY GLITTER

The feline limelight turns to the Potomac Area Cat Enthusiasts Show 10 to 6 Saturday and Sunday when more than 250 cats prance, purr and primp in competition. Veterinarian and author Jane Bicks will answer your purrsonal questions Sunday; kittens will be for sale both days. Admission to the show at the University of Maryland's Stamp Union in College Park is $4; kids 6 to 12 and seniors, $3. 860-2008. BIG SPORTS

Stretch and tuck and dunk and run at the Radenska Sports Extravaganza 9 to 5 Saturday at the Aspen Hill Racquet Club and Fitness Center, 14501 Homecrest Rd., Silver Spring. Olympic skiing gold-medalist Phil Mahre, tennis pro Dan Goldie, a few Washington Bullets and others will be on hand for exhibitions and clinics. After a 9 a.m. 5K run, there's a Bullets "shootout" at 10, skiing exhibitions at 11, more basketball at noon, the Reebok aerobics team at 1, body-building at 1:30, racquetball at 2 and tennis at 3. It's $5; $3 for under 12; part of the proceeds will help the U.S. Olympic team. Call 739-9288 for information. REST OF THE BEST

'Tis the shopping season: Armory Place, at 925 Wayne Ave., Silver Spring, is the place for two shows: the Potomac Depression Glass Show and sale is upstairs 1 to 9 Friday and 10 to 5 Saturday. $2. 654-0323. Downstairs, the Washington Bead Society will be selling beads and jewelery 10 to 4 Saturday and Sunday. $1. 587-2082 . . . the Northern Virginia Handcrafters Guild Christmas Craft Show is 1 to 5 Friday, 10 to 5 Saturday and noon to 5 Sunday at the Vienna Community Center, 120 Cherry St. SE. Free. 938-8306 . . . and the Washington Antiques Show and sale is 11 to 9 Friday and Saturday and 11 to 5 Sunday at Mount Vernon College, 2100 Foxhall Rd. NW. Three-day admission is $5; food will be for sale. Call 333-9880 (during the show) . . . The Vista International Hotel is throwing a party to celebrate the Marine Corps' Toys for Tots 40th anniversary 5 to 7 Friday, with a tree lighting, concerts and Santa at 1400 M St. NW. It's free, but bring a wrapped gift for a needy child. 429-1700.