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

ART

"John La Farge," now at the National Museum of American Art, is a fascinating show. Though in his day La Farge was considered a major American artist, his gifts were limited and spread thinly. But his breadth ensures that the show touches on many aspects of 19th-century American culture. Go to see his best work: the early still lifes and the altogether splendid stained glass pieces.

CLASSICAL MUSIC

Jean-Pierre Rampal, suffering from flu and bronchitis, has canceled his appearance with the National Symphony Orchestra, Thursday night at Wolf Trap. Instead, pianist Peter Serkin will be the soloist, with conductor Gu nther Herbig, in a program of Mozart, Beethoven and Schubert. On Friday night, also at Wolf Trap, conductor-pianist Peter Nero will join the orchestra in a tribute to George Gershwin. Herbig will be back on Saturday night, with Itzhak Perlman as soloist in a program of Brahms, Dvorak and Wagner.

Meanwhile, at the Wolf Trap Barns, a baroque opera, "L'Ormindo" by Francesco Cavalli, will have the first of four performances on Friday evening.

Also worth noting: the Manchester String Quartet, Tuesday night at the Washington Cathedral; the D.C. Youth Orchestra, Friday night at Calvin Coolidge High School; and classical saxophonist Laura Hunter, Friday night at the Corcoran Gallery.

DANCE

On Thursday night, New York Times dance critic Anna Kisselgoff, who is especially knowledgeable in the field of Russian arts of the 20th century, will present a film-illustrated lecture on the Bolshoi Ballet and its history in the Smithsonian's Baird Auditorium.

At Dance Place Friday and Saturday evenings, two area troupes, the Andrew Cacho African Drummers and Dancers and the D.C. Youth Ensemble, share what promises to be an exceptionally lively program.

FILM

"Robocop," a supercyborg created from what was left of a good Irish cop, is the most blood-curdlingly comedic thriller since "The Terminator." Peter Weller stars as the bionic being in this clever, but extremely violent, science fiction vision written by Edward Neumeier and Michael Miner of "Repo Man." Paul Verhoeven, who directed Holland's "The Fourth Man," makes his American film debut with this futuristic fantasy of a law enforcement Lazarus risen from the dead to track down his own killers.

POP MUSIC

Great American rock 'n' roll: Tom Petty and the Heartbreakers, the Del Fuegos and the Georgia Sattellites, all at the Merriweather Post Pavilion on Monday.

The old rugged face: Merle Haggard. At Wolf Trap on Tuesday with an excellent newcomer, singer-songwriter Lyle Lovett.

Eric Bogle, Australia's premiere folk singer, and writer of classics like "And the Band Played Waltzing Matilda," is at Ireland's Four Provinces on Tuesday.

Together again: Burt Bacharach and Dionne Warwick, at Wolf Trap on Wednesday. THEATER Everyone knows that "Cats" is back at the National, with its paws on a bigger box office take than the first time around. Some other deserving summer fare in these dog days: Ian McKellen's informal, intimate "Acting Shakespeare" enters its last week at the Olney; Washington playwright T.J. Edwards' unsettling comedy "National Defense" slam-dances into Woolly Mammoth's summer home at Washington Project for the Arts; and "The Immigrant," an unabashedly sentimental play about a Jewish immigrant planting his roots in Texas, is winning hearts at Arena's Kreeger Theater.