Scottish Walk

Alexandria celebrates its Scottish heritage with its annual Scottish Christmas Walk, a weekend festival that features:

* The Scottish Christmas Walk Parade Saturday from 10:30 to noon, with more than 100 Scottish clans, pipe and drum corps, dog clubs, antique cars and other attractions. It follows a winding route from South Pitt and Wilkes streets to South St. Asaph and Wolfe streets. Call

703-549-0111.

* Seven Alexandria homes, decorated for the holidays by interior designers, are open for tours Saturday from 11 to 4. Tickets are $15 in advance, $20 Saturday; get them and a guide at the Campagna Center, 418 S. Washington St. Call 703-549-0111 for more information.

Wolf Trap Singalong

The United States Marine Band will lead a holiday singalong Sunday at 4 at Wolf Trap's Filene Center, 1551 Trap Rd., Vienna. Admission is free, but donations of canned goods will be accepted. Free shuttle buses will run to Wolf Trap from the West Falls Church Metro starting at 2:30, and back after the concert. Call 202-433-4011 or 703-255-1860.

Audubon Holiday Fair

Arts and crafts created by 115 juried artisans, holiday greenery, gourmet foods, a live animal exhibit and craft activities for children are showcased at the Audubon Holiday Fair Saturday and Sunday from 10 to 5 at Woodend, the society's 44-acre preserve at 8940 Jones Mill Rd., Chevy Chase. Admission is $7, ages 2 through 12 $3 (younger free). On Friday, a preview party is held from 7 to 10, with gourmet desserts and entertainment. Admission to the party is $35; $10 for ages 2 through 12 (younger free). Free shuttles will run from North Chevy Chase Elementary School, 3700 Jones Bridge Rd., and the Waverly Street public parking lot near the Bethesda Metro. Call 301-652-9188.

Holiday Sounds

* The Barnes and Hampton Consort presents "A Celtic Christmas" Saturday at 4 and 8, Sunday at 4, Thursday at 7, Dec. 13 at 8 and Dec. 14 at 4 and 8 at Dumbarton Church, 3133 Dumbarton St. NW. Tickets are $26, $22 seniors and students. Call 202-965-2000.

* The University of Maryland Chorus presents holiday concerts Saturday at 8 and Sunday at 3 and 7:30 at the Concert Hall of the Clarice Smith Performing Arts Center, on the corner of Route 193 (University Boulevard) and Stadium Drive on the campus of the University of Maryland. Tickets are $20, $18 seniors, $5 students. Call 301-405-2787.

* The Washington Women's Chorus presents a concert of carols from around the world on Saturday at 7 at St. Patrick's Episcopal Church, 4700 Whitehaven Pkwy. NW and Sunday at 4 at St. Andrew's Episcopal Church, 4000 Lorcom Lane, Arlington. Tickets are $18, $15 seniors and students. Call 202-244-7367.

BlackRock Opens

Germantown's BlackRock Center for the Arts holds a grand opening Saturday from noon to 3 with a Rock Around the Clock celebration, with '50s music, hula-hoop contest, best-dressed '50s costume contest and a family show at 2 featuring Los Quetzales. Everything is free but concert tickets, which are $6.50. In the evening, festivities continue with a cocktail reception from 6:30 to 8, followed by "Danny & Sylvia" in the Main Stage Theater and a New York-style dance cabaret in the Dance Theater (tickets $80 for reception and cabaret, $125 for the reception and "Danny & Sylvia"). The center is at 12901 Town Commons Dr., Germantown. Call 301-528-2260.

Sesame Street Live

Sesame Street Live brings "1-2-3 . . . Imagine!," an adventure with Big Bird, Elmo, Rosita and the rest of the Sesame Street neighborhood, to Patriot Center at George Mason University, 4400 University Dr., Fairfax. Shows are Thursday at 7, Dec. 13 at 10:30 and 7, Dec. 14 at 10:30 and 2:30 and Dec. 15 at 1 and 4:30. The show then moves to the D.C. Armory, 2001 East Capitol St. (Metro: Stadium/Armory) for performances Dec. 26-29. Tickets are $13, $16 and $21, plus service charges, through Ticketmaster, 202-432-7328.

'The Christmas Revels'

The Washington Revels present "The Christmas Revels," a Victorian celebration of Christmas on Friday at 7:30, Saturday at 2 and 7:30, Sunday at 2, Dec. 13 at 7:30, Dec. 14 at 2 and 7:30 and Dec. 15 at 2 at Lisner Auditorium, 730 21st St. NW (Metro: GWU/Foggy Bottom). Tickets are $18-$38, ages 18 and under $12-$20 (50 percent off youth tickets on Friday nights). Call Ticketmaster at 202-432-7328 (service charges added).

Improv Festival

Twenty groups and 77 dancers, performance artists and musicians take part in the International Improvisation Plus+ Festival Friday and Saturday at 8 at the Marvin Center Betts Theatre, 8001 21st St. NW (Metro: Foggy Bottom/GWU) and Dec. 14 at 8 and Dec. 15 at 7 at the Jack Guidone Theater at Joy of Motion Dance Center, 5207 Wisconsin Ave. NW. Tickets to the Marvin Center shows are $15, $8 students; call Ticketmaster, 202-432-7328 (service charges added). Tickets to the Dec. 14-15 shows are $15, $12 students and seniors. Call 202-362-3042.

Family Folk Songs

Cathy Fink and Marcy Marxer, with special guest Ella Jenkins, present their annual Family Holiday Concert on Saturday at 1 and 3:30 at the NOAA Auditorium, 1301 East-West Hwy., Silver Spring (Metro: Silver Spring). Tickets are $10 in advance, $12 at the door. Call 301-754-3611.

Festival of Lights

The Washington Temple of the Church of Jesus Christ of Latter-day Saints' annual Festival of Lights is open through Jan. 1 at the Temple Visitors Center, 9900 Stoneybrook Dr. in Kensington. The festival is open 5:30 to 10 p.m. nightly. It features more than 300,000 colorful lights on the grounds, a display of 20 beautifully decorated trees and nightly concerts at 7 and 8. Admission is free. Call 301-587-0144.

-- Compiled by Larry Fox

More than 100 clans will march in Alexandria's Scottish Christmas Walk on Saturday."Sesame Street" characters come to town.