* The Franz Liszt Centennial Celebration will be the major musical event in Washington this week, with free concerts, lectures and master classes at the Library of Congress, the Washington Cathedral and St. Matthew's Cathedral.

Three of the finest living Liszt pianists, Jerome Rose, Jorge Bolet and Russell Sherman, will give recitals in the Smithsonian's Baird Auditorium. Also in the Baird will be programs devoted to Liszt's superb, neglected vocal music and his small but choice repertoire for violin and piano.

The Mostly Mozart Festival opens Wednesday night at the Kennedy Center with Gerard Schwarz conducting and pianist David Bar-Illan, flutist Carol Wincenc and harpist Heidi Lehwalder as soloists. Concerts will continue every evening through Saturday, with a pre-concert recital at 7:30 and post-concert dancing on the riverside terrace.

The National Symphony opens the week, tonight at Wolf Trap, with a pops concert featuring pianist Peter Nero. Friday night's program, also at Wolf Trap, will feature music inspired by Shakespeare, with Neville Marriner conducting.

Tuesday night's program in the Library of Congress Summer Chamber Music Festival will include Mozart's rarely heard Adagio in C minor for glass harmonica and Saint-Saens' popular "Carnival of the Animals."

Also worth noting: Pianist Eugene Gaub, tonight at the National Gallery; Mozart's "Abduction from the Seraglio," presented by the Capitol Opera, Saturday night and next Sunday at the Reston Community Center. DANCE

The exhilarating KanKouran, a local troupe specializing in West African dances and rituals, presents a free performance and post-performance discussion this afternoon at the New Dance Place. Washington Dance Directions '86: A Festival of Premieres concludes this week, starting Thursday evening, with three programs at the Marvin Theatre showcasing nine modern dance companies and solo artists resident in the Washington area. The unusual dance-theater troupe Momix makes its area bow Saturday night with a program at Tawes Theatre as part of the University of Maryland's annual summer arts festival. FILM

The Joseph Mankiewicz tribute concludes at the American Film Institute this week with "The Barefoot Contessa," "Julius Caesar" and "All About Eve," at the screening of which (Wednesday night) Mankiewicz will appear.

The Real Life America series concludes at the Library of Congress' Mary Pickford Theater Wednesday with "La, La, Making It in L.A." and "Gates of Heaven," together a journey into that peculiar state of mind known as Los Angeles. Friday, the American Satire series concludes with Preston Sturges' "Sullivan's Travels."

Thursday through Saturday at the Sidwell Friends school, Eric Rohmer's "Claire's Knee."

The Summer Cinema series continues at the National Theatre tomorrow with "A Star Is Born."

Among current releases, Robert Redford's comeback performance in "Legal Eagles," an otherwise unexceptional comedy; the extraordinary aerial photography of "Top Gun," an otherwise unexceptional drama. THEATER

"Biloxi Blues (at the National Theatre) is the second installment in Neil Simon's autobiographical trilogy, and it's every bit as entertaining as the first, "Brighton Beach Memoirs." Its hero, Eugene Morris Jerome, is now in the Army, but he's learning more than just discipline. He's awakening to the wide world and his adventures are as funny as they are heart-warming. Today is your chance to catch the National Theatre of Great Britain's imaginative rendering of "Animal Farm" (Morris Mechanic Theatre in Baltimore), in which Farmer Jones' animals attempt to establish, unsuccessfully, a classless barnyard