Seven young musicians from the Middle Atlantic region, winners of a special competition, will be featured this afternoon at the Wolf Trap Barns in the final performance of The Barns' Brahms Festival. This program, the most varied of the festival, will include solo piano music and Lieder as well as the Clarinet Trio and the Violin Sonata in D minor.

The American premiere of Gounod's opera "Mireille" is being offered in a semi-professional concert performance by the Potomac Valley Opera Friday night and Sunday evening in St. John's Church, Lafayette Square. Other events likely to prove unusually interesting include Mstislav Rostropovich's interpretation of Schubert's Ninth Symphony this week with the National Symphony Orchestra, a concert by the Academy of St. Martin-in-the-Fields Saturday night at the Kennedy Center, and a recital by pianist Santiago Rodriguez Saturday night at the University of Maryland. Pop

Well, that Boy George (O'Dowd) has made believers out of those who saw him as little more than a curiosity; "Do You Really Want to Hurt Me?" is a Top Ten hit, and his band, Culture Club, is poised to be the next big band out of England. Washingtonians can decide for themselves at the Wax Museum tonight.

Part of WAMU's annual winter bluegrass festival is a super concert and this year the station has lined up the Seldom Scene, ex-Scener John Starling and his Ready Section Band and those staunch young traditionalists, the Johnson Mountain Boys. Showtime is 3 p.m., today at Lisner Auditorium.

Guitar heaven? No, just the Capital Centre on Monday night when Eric Clapton, Albert Lee and Ry Cooder play with strings attached.

For a little blues in the night, check out Charlie's Georgetown this week when Jimmy Witherspoon and Carrie Smith explore that classic genre from his and hers points of view. Dance

Once again, a week brimming with dance events of exceptional interest. Today brings the final performances of the Joffrey Ballet at the Kennedy Center Opera House, and the program by jazz tap masters Jimmy Slyde and Steve Condos at the Smithsonian's Baird Auditorium, and tonight, the last performance of solo works, new and old, by pioneer Washington choreographer Pola Nirenska. Tuesday evening, the Dance Theatre of Harlem commences a week of programs at the Kennedy Center Opera House featuring four area premieres, including the rarely seen "Les Biches" by Bronislava Nijinska, and George Balanchine's "Square Dance." Thursday night, the Greg Reynolds Dance Quintet, fresh from its New York appearance, presents the first of three performances at the Washington Project for the Arts, and on Friday and Saturday evenings, the New York-based Gail Conrad/Tap Dance Theater makes its area debut at The Barns at Wolf Trap. Next Saturday and Sunday, gifted Washington choreographer Sharon Wyrrick presents her troupe, Full Circle, in a program of new and recent repertory at the Dance Place. Film

The great new Italian film "The Night of the Shooting Stars," at the K-B Janus. Also, the continuing engagements of "The Year of Living Dangerously" and "The Sting II" at area theaters, "Smash Palace" exclusively at the MacArthur, "The Personals" exclusively at the Outer Circle, and the five Oscar nominees for best movie--"E.T.," "Gandhi," "Missing," "Tootsie" and "The Verdict"--at area theaters; the revival of the Astaire-Rogers double-bill of "Follow the Fleet" and "Swing Time" at the Biograph today and tomorrow, plus special matinee showings today of Tom Davenport's charming dramatic shorts "From the Brothers Grimm"; revivals this week at the American Film Institute Theater of two more Astaire-Rogers musicals, "The Gay Divorcee" and "Shall We Dance," plus the silent romances "Love" with Garbo & Gilbert and "Son of the Sheik" with Valentino, and a vintage DeMille mind-boggler from the early '30s, "Madam Satan." Theater

Last week to see "Out of the Reach of Children," Cornelia Ravenal's original musical at New Playwrights' Theater.

And Shakespeare's "Pericles," in its imaginative, New Wave-tinged incarnation by the Acting Company, extends its run through March 5 at the Kennedy Center Terrace Theater. Art

"Painting in Naples From Caravaggio to Giordano," a glorious, often ghastly show of sacred Italian art. To see it is to tremble. At the National Gallery of Art.

"Alfred Stieglitz"--This, the first retrospective exhibition of the great American photographer's work in almost 50 years, includes a number of his finest photographs among the 170 prints on view. At the National Gallery of Art.

The "38th Corcoran Biennial Exhibition of American Painting/The Second Western States Exhibition"--A vivid, entertaining exhibition by 30 modernist artists from western states. At the Corcoran Gallery of Art.