ALEXANDRIA'S year-long birthday party peaks this weekend, which marks the 250th anniversary of the sale of the first building lots under the city charter approved by the Virginia General Assembly in 1749. The highlights of the celebration are the premiere of Garrison Hull's "Riverside Sonata" at the Lyceum and a picnic and fireworks show at Jones Point Park.

The sonata, commissioned by the city from a native son, will be performed at 3 Saturday by pianist Christine Hagan at the Lyceum, the city historical museum at the corner of Prince and South Washington streets. Hagan also will play other concert pieces "relevant to the city." Admission to the one-hour event is free, but all seating is reserved; call 703/838-4994.

Festivities at Jones Point Park, off South Royal Street under the Woodrow Wilson Bridge, begin at 6 p.m. A musical program opens with the Alexandria Pipes & Drums. The city's official birthday cake will be cut and served after an awards presentation ceremony at 7. The Alexandria Symphony Orchestra, led by Kim Allen Kluge, will present a program culminating with Tchaikovsky's "1812" Overture, complete with real cannons. Fireworks will begin at 9:30.

Refreshments will be available for sale but, better still, bring your own picnic, blankets and lawn chairs. The rain date is Sunday (for fireworks only).

OTHER PUBLIC ACTIVITIES in the city this weekend, plus highlights from other city events scheduled through the summer and fall:

FRIDAY from 10 to noon: Children are invited to the Carlyle House, 121 N. Fairfax St., to learn how to play 18th-century games. Suggested donation $1 per child. 703/549-2997.

FRIDAY at 7:30: Free concert by the Alexandria Citizens Band in Market Square, 300 King Street. 703/883-4686

SATURDAY at 10 and 1:30: Alexandria Dig Day. Site TBA. Help the city's archaeologists excavate an early building site. $5 per person. 703/838-4399.

SUNDAY from 3 to 5: Rededication of the 1785 Alexandria Academy, Virginia's first free school, corner of Wolfe and Washington streets. Free. Trustee George Washington donated 1,000 pounds to the Academy for the education of 20 orphans. 703/549-5811.

JULY 12, 19 & 26 at 7: Free band concerts at Waterfront Park, foot of Prince Street. 703/883-4686.

JULY 14 from 6 to 9: Free concert by the band Crystal Brass at the Landmark Mall food court. 703/354-8405 or 703/941-2582.

JULY 23 from 7 p.m. to 1 a.m.: Alexandria's 250th Birthday Ball at the Hilton Alexandria. Black tie, $75 per person. 703/838-4554.

JULY 22-25: 26th Annual Virginia Scottish Games & Festival.

u July 22 at 8 p.m. -- Concert by harp competition judges Alison Cainnard and Marie-Louis Napier at George Washington Masonic Memorial, 101 Callahan Dr. $15. 703/683-2007.

u July 23 at 8 p.m. -- Scottish Country Dance at the Durant Senior Center, 1605 Cameron St. Free for spectators, dance fee $12. 703/838-6323.

u July 23 from 9 to 11 p.m. -- Clandestine & MacKeel in concert at the Birchmere, 3701 Mount Vernon Ave. Tickets $18; call 1-888/311-5455.

u July 24 at 8 to 8 -- Games and festival open at Episcopal High School, 3901 W. Braddock Rd. Competitions include professional and amateur events involving lifting and throwing heavy things, some of which could pass for telephone poles; piping; drumming; fiddling; and dancing. There will be children's games, a pub tent and Scots heritage society information centers. At 5 p.m. there will be a "retreat with massed bands and an artillery salute."

u July 25 from 8 to 6 -- Scottish church services, U.S. National Highland Heptathlon and Masters competitions and East Coast amateur championship, British car show, harp and pipe band performances, parades of Scottish breeds and clans and a Celtic craft festival. Closing ceremonies at 4.

The festival information number is 703/912-1943; the Web site is www.vascottishgames.org.

JULY 24 from 9 to noon: Second annual "From Clutter to Culture" yard sale, Alexandria Black History Resource Center, 638 N. Alfred St. 703/838-4356.

JULY 24 from 1 to 4: A turn-of-the-century ice cream social at the Lyceum, 201. S. Washington St. Admission free, ice cream tickets $1. 703/799-8229.

JULY 29 at 7:30: "Jumping Jim Crow: White Elites and Black Protest in Alexandria, 1919-1939," free lecture by J. Douglas Smith of the California Institute of Technology, at the Lyceum, 201 S. Washington St. 703/838-4994.

JULY 31 from noon to 6: African-American Heritage Festival at Market Square, 300 King St. 703/838-4844 or 703/838-4994.

JULY 31 from 8:30 to midnight: A Midsummer Night's Ball (Viennese waltzing) at Gadsby's Tavern Museum, 134 N. Royal St. Tickets $20 in advance, $25 at door. 703/838-4242.

AUG. 1, 8, 15, 22 & 29 at 3: Free Mount Vernon chamber music series at the Lyceum, 201 S. Washington St. 703/549-2997.

AUG. 1 from noon to 4:30: Free housewarming, Carlyle House, 121 N. Fairfax St. Tours, refreshments and music in celebration of the family's taking up residence there on Aug. 1, 1753. 703/549-2997.

AUG. 1 from noon to 4:30: Free Tavern Day at Gadsby's Tavern Museum, 134 N. Royal St. A re-creation of 18th-century tavern life. 703/838-4242.

AUG. 2 & 9 at 7: Free concerts at Waterfront Park, foot of Prince Street. 703/883-4686.

AUG. 4, 11 & 18 at 12:15: Free Lunch Bunch concerts in Market Square, 300 King St. 703/883-4686.

AUG. 5, 12 & 19 at 7: Music at Twilight concerts, Fort Ward Park, 4301 W. Braddock Rd. 703/883-4686.

AUG. 6 & 20 from 10 to noon: Children are invited to the Carlyle House, 121 N. Fairfax St., to learn how to play Colonial games. Suggested donation $1 per child.

AUG. 6 & 20 at 7:30: Alexandria Citizens Band concerts at Market Square, 300 King St. 703/838-4844 or 703/883-4686.

AUG. 7 from 10 to 3: Friendship Firehouse Festival. Displays and demonstrations on fire safety and rescue at the 1855 edifice. Children get free balloons, fire hats and cake. 703/838-3814 or 703/883-4686.

AUG. 7 at 10 and 1:30: Alexandria Archaeology Dig Day. Site TBA. Help city archaeologists excavate a historic site. $5 per person. 703/838-4399.

AUG. 8 at 8: Performance of the musical "1776" to benefit the city's anniversary celebration. Little Theatre of Alexandria, 600 Wolfe St. $20. 703/838-4554.

AUG. 11 from 6 to 9: Free anniversary music series, blues and swing concert and dance at Landmark Mall food court. 703/354-8405 or 703/941-2582.

AUG. 13 at 7:30: Alexandria Harmonizers concert, Market Square, 300 King St. 703/838-4844 or 703/883-4686.

AUG. 14 from noon to 6: Irish Festival at Waterfront Park, foot of Prince Street. Free. 703/838-4994.

AUG. 21 from noon to 6: American Indian Festival at Waterfront Park, foot of Prince Street. Free. 703/838-4844 or 703/883-4686.

SEPT. 5 & 19 at 3: Mount Vernon Chamber free music series, Lyceum, 201 S. Washington St. 703/838-4994.

SEPT. 8 from 6 to 9: Octoberfest band concert at Landmark Mall food court. 703/354-8405 or 703/941-2582.

SEPT. 9 at 7:30: Alexandria Maritime Heritage Series lecture, Lyceum, 201 S. Washington St. 703/838-4994.

SEPT. 10, 11 & 12 at dusk: Caravan Stage Barge production of "The Tale of the Whale" aboard a replica Thames River sailing barge at Jones Point Park, off South Royal Street under the Woodrow Wilson Bridge. $15 adults, $10 students and seniors, $4 children. 703/838-4200, Ext. 654.

SEPT. 11 from noon to 6: Italian Festival at Market Square, 300 King St. 703/

838-4844 or 703/883-4686.

SEPT. 11 & 12 from 9 to 5: The Colonial Fair at Mount Vernon. Fourscore leading American traditional craftspersons demonstrate their work and wares. Colonial music, entertainment and food. Regular admission. 703/780-2000.

SEPT. 12 at 4: Free recital at Lyceum, 201 S. Washington St. 703/838-4844.

SEPT. 18 & 25 at 10 and 1:30: Alexandria Dig Days. Site TBA. Help city archaeologists excavate a historic site. $5 per person. 703/838-4399.

SEPT. 18 at 1: Lecture on "the 5th New York Veterans: Duryee's Zouaves in Alexandria" by historian Patrick A. Schroeder at Fort Ward Museum, 4301 W. Braddock Rd. $5, reservations suggested. 703/838-4848.

SEPT. 25 from 10 to 3: The 59th annual tour of Alexandria historic homes. $20 per person. 703/683-3279.

SEPT. 25 from 11 to 6: 19th Annual Hard Times Chili Cook-Off, to benefit American Kidney Foundation. Oronoco Bay Park, riverfront between Pendleton and Madison streets. $5. 202/244-7900.

SEPT. 26 from 1 to 4: "Time Travels: Help the Colonists Prepare for Winter." Costumed, guided, hands-on tour of Gadsby's Tavern Museum, 134 N. Royal St. $4 adults, $2 children 11-17. Free to Girl Scouts and children under 10 if pre-registered. 703/838-4242.

SEPT. 30 at 7:30: "In Search of Family Treasures: the Story of Entrepreneur Madam C.J. Walker." Free lecture by genealogist A'leila Bundles, Walker's great-great granddaughter. Lyceum, 201 S. Washington St. 703/838-4994.

OCT. 2, 10 to 5: Free Scottish Heritage Fair at Fort Ward Museum, 4301 W. Braddock Rd. 703/838-4844.

OCT. 2 & 3, 10 to 5: Visit of Jamestown Settlement Ship Susan Constant. The 116-foot vessel, a replica of one of the three ships that brought colonists to the first permanent English settlement in North America, will be open for visitors to explore free, at Founders Park, riverfront between Cameron and Oronoco streets.