All right,so you've heard a few versions of Handel's "Messiah." But its performance today by the Washington Philharmonic Orchestra may be different.

The orchestra is hosting the concert to benefit AIDS education.

"I don't know of any other performing arts groups in the area that are directing their energies toward education about the disease," says conductor Darrold Hunt, who started the Urban Philharmonic Society after his graduation from the Juilliard School in 1970. "Our goal is to alert as many people as possible ... that everyone must take responsibility in fighting the AIDS plague," Hunt says.

The concert begins at 4 p.m. and will be held at the Metropolitan A.M.E. Church, 1518 M St. NW. Tickets are $15, or $7.50 for senior citizens and students with valid ID. For more information, call 347-0447.

-- Cristina Del Sesto PINING AWAY FOR ART

The 11th annual "Trees of Christmas" exhibition opens Friday at the Smithsonian's National Museum of American History, culminating a year-long community effort toward an educational experience in the arts.

"It's a horticulture display with artists using their own particular media to decorate a Christmas tree," says coordinator Dixie Rettig, a needlework historian for the Smithsonian's Resident Associate Program for Studio Arts. "It's the general education of how Christmas trees are done in various areas of the country."

Coproduced by the Smithsonian's Office of Horticulture and the museum's Office of Exhibits, the exhibition displays 10 trees ranging from eight to 12 feet in height, each decorated in a different theme or tradition. For example, the tree entitled "Christbaumschnitte" is decorated with ornaments from the German and Swiss tradition of detailed, three-dimensional cut-paper designs with hand-sewn flowers, birds and other Christmas symbols. Another tree's decorations consist of macrame'd bells, snowflakes, angels, and stars made of square knots, double-half hitches and half knots, prepared by a women's senior citizen group.

The exhibition continues through Jan. 6 and admission is free. The museum is open from 10 a.m. to 5:30 p.m. daily. For more information call 357-2700. -- David J. Marek GLASNOST LIT

Guess who's coming to dinner at Susan Richards Shreve's house?

After a week of summit overload, the Russians are coming. Again.

Shreve, author of "Queen of Hearts" and president of the PEN/Faulkner Award Foundation, thought it important for the five Soviet authors in town for a reading at the Folger Shakespeare Library to meet American writers in a private, informal setting.

The Soviet Writers Union, an organization of professional writers, and the PEN American Center, the international association of writers based in New York, joined forces for the first time to bring the Soviets and their work to audiences in New York, Boston and Washington. What makes this literary delegation unique is, "These are not party-chosen authors," says Shreve. "Members of PEN selected Russians on the basis of who was best, and in the spirit of glasnost, the Soviets arranged for these authors to be made available for the readings."

On Monday at 8 p.m., American authors including Robert Stone, Larry McMurtry and Carolyn Forche will introduce Soviet authors Fazil Abdulevich Iskander, Daniil Aleksandrovich Granin, Aleksander Semyonovich Kushner, Yunna Petrovna Morits and Viktor Petrovich Golyshev. Each Soviet will read a selection from his or her work in Russian and then an American will read a longer, translated excerpt from the same piece.

Admission to the event at the Folger is free; however, tickets are required for admission.

Tickets (limit two per person) are available at Ticketplace. Call 544-7077. -- Teresa Moore CHRISTMAS ALTERNATIVES

Today at 3 p.m., the Bethune Museum inaugurates a new Christmas tradition: Marita Golden, author of "A Woman's Place," and the D.C. Youth Ensemble, will present an afternoon of Christmas stories and music in the Victorian home of renowned educator Mary McLeod Bethune.

Golden, president of the African American Writer's Guild, will read a selection of alternative Christmas fiction: a story from Langston Hughes' collection "The Ways of White Folks," an excerpt from Margaret Walker's novel "Jubilee," depicting Christmas among the slaves on a plantation, and a tale of Kwanzaa by local author Sharon Bell Mathis.

Golden points out that although Kwanzaa is observed near Christmastime, "It is a cultural, rather than religious holiday," created by and for African Americans ambivalent about Christmas as it is celebrated in this country.

And Kwanzaa principals of unity, collective work, faith and creativity will spring to life when members of the D.C. Youth Ensemble, a troupe of actors, singers and dancers that has opened for Melba Moore and Phyllis Hyman, lift their voices in classic Afro American Christmas hymns and spirituals.

Admission for the two-hour program is $2. Refreshments will be served after the performance at 1318 Vermont Ave. NW. Call 332-1233 for further information. -- Teresa Moore RICHIE COLE'S SYNTHESIS

Richie Cole, who with his band Alto Madness will be performing with jazz guitarist Emily Remler tomorrow night at Blues Alley, says his new album, five years in the making, is everything its title suggests. "Popbop" is an eclectic compilation of popularized bebop-type tunes.

"My whole career I've had the problem of people, reviewers trying to put me in a category," Cole says. "I wanted to create my own category, a new category of jazz that includes everything from the Latin instrumental of 'La Bamba' to the blues of 'L. Dorado Kaddy.' " " 'Popbop' is bringing jazz to the people," Cole explains. "It has no limits. I play everywhere, from South Dakota to Tahiti."

Along with Remler at Blues Alley tomorrow night, Cole will be playing with two members of his Alto Madness: bassist Eddie Howard and drummer Steve Williams. Tickets are $15, and performance times are 8 p.m. and 10 p.m. For more information, call 337-4141. -- Claudia Sandlin THE SOUNDS OF SCIENCE

Sciencemerges with music when National Musical Arts performs in the visually intriguing and acoustically fantastic geodesic auditorium of the National Academy of Sciences. "There is a sympathetic relationship between science and music, a historical one going back to the ancient Greeks," says pianist Patricia Gray, artistic director of the chamber ensemble. "The National Academy of Sciences is the capstone of science in this country, but it wishes also to serve the community of Washington and put forth significant musical performances of a far-reaching nature."

As the ensemble-in-residence of the academy's "Arts in the Academy" program, National Musical Arts is a consortium of 13 musicians from orchestras around the country that performs here five times a year. In addition to the National Symphony Orchestra, members come from the Rochester Philharmonic, the Cincinnati Symphony, the St. Paul Chamber Orchestra and the New Haven Symphony.

Joining Gray for Saturday night's performance will be violinists Rebecca Culnan and Paul Kantor, violist Melissa Micciche and cellist David Teie. The program will feature Dvorak's intimate Terzetto for Two Violins and Viola, Debussy's Sonata for Violin and piano -- his final composition -- and Schumann's monumental chamber work, the Quintet in E flat for Piano and Strings. The concert begins at 8 p.m. and is free to the public. For information, call 334-2436. -- Alex Stoll A CAREER IN BLOOM

His name is Luka, he sings on the second floor of Dylans in Georgetown. And Irish singer/songwriter Luka Bloom couldn't be happier about his life. He just changed his name. "I used to be Barry Moore, Christy Moore's brother. Now I'll be judged without preconceptions," says Bloom of his famous sibling, the premiere Irish singer today. "I thought 'Bloom' had a nice Irish literary ring to it {from James Joyce's "Ulysses"} and 'Luka' yes, it came from the song {Suzanne Vega's popular "Luka"}."

He's completed a new record, filled with his acoustic compositions, and has been compared to Pete Townshend and Vega. And he's emigrated permanently to the States, setting up house here in Washington. Bloom will be playing at Dylans every Monday beginning at 9 p.m. into the new year.

-- Mairi N. Morrison