The Washington Post critics choose their favorite shows of the week.

ART

Head for the Corcoran Gallery of Art and get a glimpse of the enigmatic "Platform" by Alex Castro. At once a drawing and a sculpture, it's limitless, with a beauty so subtle that inattentive viewers don't even know it's there. Also don't miss "Spectrum: Three Sculptures," a gathering of recent works by Chris Wilmarth of Manhattan, John Duff of California and Washington's Peter Charles. It's first-rate.

CLASSICAL MUSIC

Benjamin Britten's massive and magnificent "War Requiem" will be the main attraction for the National Symphony Orchestra this week, with Mstislav Rostropovich conducting and Galina Vishnevskaya singing the part composed for her by Britten. The program will also include Britten's brief "Praise We Great Men," commissioned by the NSO but left incomplete at Britten's death. Music of Britten will also be on the program, as well as music of Vaughan Williams and others, when the Washington Men's Camerata performs at St. Margaret's Episcopal Church Saturday night.

The Smithsonian's American Sampler Festival, at noon Saturday in the Hall of Musical Instruments, will include music for glass harmonica, keyboards, chorus and various other old instruments, focusing on the period before 1800.

Today's highlights around town: Wondrous Machine at St. Alban's Church; the Washington Bach Consort at the Church of St. Agnes and the Ascension; the Manchester String Quartet at the Phillips Collection; the National Gallery Orchestra, George Manos conducting, in the East Garden Court; and soprano Amanda Balestrieri at the Lyceum, Alexandria.

Also worth noting: Pianist William Doppman, Wednesday night at Montgomery College.

DANCE

CoDanceCo, a highly reputed contemporary dance repertory company based in New York, completes its area debut series at Dance Place this evening. "Dances by Three Choreographers," at Dance Arts Moving Arts Theater Friday and Saturday evenings, offers work by Washingtonians Richard Dunston, Nancy Havlik and Elly Porter. Works choreographed by Rex Bickmore to music by Poulenc, Jacques Brel and Claude Bolling will be featured in a program of "Chamber Ballet," at the French Embassy Friday and Saturday night; dancers will be from the Ballet Center of Washington. At Dance Place Friday through Sunday evenings, "Bliss, Buckley, McDonald" will offer the combined talents of three area dancers and a varied array of contemporary dance works.

FILM

In "The Stepfather," the new film starring Terry O'Quinn and Shelley Hack, Daddy's mad -- really mad. "The Stepfather" is a psychological thriller, not a domestic drama, but it may be the best movie about the breakup of a family since "Shoot the Moon." Directed by Joseph Ruben, from a beautifully crafted script by Donald E. Westlake, "The Stepfather" deals with family tensions and the pressures of living up to the great American dream in horror movie terms. It's a terrific movie -- like Halloween at the Cleavers.

POP MUSIC

It's time for the annual Washington Folk Festival and on Monday there's a benefit dance concert at Glen Echo's Spanish Ballroom featuring the Cajun band Beausoleil and local zydeco band Little Red and the Renegades (there's also a Cajun covered-dish potluck starting at 5:30); the festival itself, featuring many local but multicultural and ethnic performers, takes place all over Glen Echo Saturday and Sunday, for free.

Nostalgia abounds with the stars of the show "Beatlemania" at the Bayou on Tuesday. And for those wanting to remember the Summer of Love with an American accent, Spirit and Canned Heat share a bill at the 9:30 club on Wednesday.

Wolf Trap resembles Grand Central Station this week: On Wednesday, it's Wolf Trap's Opening Gala, with everyone from Ashford and Simpson, Burt Bacharach and Carole Bayer Sager, Roberta Flack, Tony Bennett and Henry Mancini to Randy Travis, Beverly Sills and Morton Gould. Then on Saturday, it's a tribute to a half century of invention from Dizzy Gillespie and the cast of characters includes Wynton Marsalis, Freddie Hubbard and Jon Faddis, and that's just the trumpet players.

THEATER

If you've ever wondered where Tina Turner, Millie Jackson and other hot mamas learned to shake and quake and raunch and roll, "The Late Great Ladies of Blues & Jazz" has your answer. At Arena's Kreeger Theater, Sandra Reaves-Phillips recalls the earthy essence of those good old bad girls Ma Rainey, Bessie Smith, Ethel Waters, Billie Holiday and Dinah Washington; then she cleans up her act and takes the audience to heaven with a rolling, thunderous tribute to Mahalia Jackson.