Not many classical music events -- if classical is the right word -- of the entire year could outdo the potential for celebrity appeal of this coming Friday's concert at the Capital Centre of zarzuela, the marvelous -- and in this country, at least -- little known Spanish form of operetta. The star is Placido Domingo.

Perhaps it will be a lucrative venture for him, but this tour is also a labor of love by the fabulous tenor. His parents were celebrated singers of zarzuela, and he had always planned to do the same himself if he didn't make it big in opera by age 30.

What happened to Domingo in opera is, of course, history. Thus it will be all the more a luxury to hear him in this lovely, if sometimes less demanding, music.

Other events: Mstislav Rostropovitch's two preview concerts on Saturday and next Sunday at Wolf Trap of works being prepared for the National Symphony Orchestra's September-long tour of Europe. And Sunday on the Capitol's West Lawn, Hugh Wolff will conduct the National Symphony for the last time as associate conductor. Wolff will become the music director of the New Jersey Symphony. Sunday's program includes works by Berlioz, Stravinsky, Gershwin, Copland, Sousa and Cole Porter. DANCE

The John Curry Skaters complete a three-week run at the Kennedy Center Opera House with repeat performances of all three programs, Monday through Saturday, with matinees Wednesday and Saturday. The D. C. Youth Ensemble presents a revised version of its splendid minstrel show, now prefaced by a parade, at St. Martin's Church on Capitol Hill Thursday evening, and at Union Temple Church on 14th Street SE on Saturday afternoon. Contemporary dancers Diane Frank and Deborah Riley, from New York, present an informal performance and Meet the Artist Evening (inaugurating a new series) at the Dance Place Saturday night, in conjunction with Perlo/Bloom & Company and workshop participants. FILM

Shohei Imamura has given Washington an embarrassment of riches. Opening Friday for a one-week run at the Biograph, his "Vengeance Is Mine" is a sterling example of his odd and reckless talent. Still at the Key: "The Ballad of Narayama."

The Smithsonian Resident Associates will screen Charlie Chaplin's "The Gold Rush" Tuesday. Call 357-3030 for details.

The American Film Institute will screen the Preston Sturges comedy classic "Sullivan's Travels," starring Joel McCrea and Veronica Lake, Friday at 7 p.m., and a number of British comedies out of the Ealing Studio all week long. Call 785-4601 for details.

The Blue Collar Thirties series at the Library of Congress' Mary Pickford Theater continues with "The Public Enemy," starring James Cagney, Tuesday at 5:30 and 7:30 p.m. Wednesday, the Jason Robards series continues with "All the President's Men," Alan Pakula's masterfully managed, complex thriller about you-know-who. POP MUSIC

Paul Young's soul-grit vocals have made him a monster act in England, and America is just getting to know him better through gems like "Every Time You Leave"; he tops a bill with Nik Kershaw at Merriweather Post Pavilion tonight.

There aren't too many genuine legends left in rock 'n' roll: Roy Orbison is one of them. He's at the Bayou on Monday.

Now into its third decade, the Art Ensemble of Chicago continues making some of the most adventurous, uncompromising jazz around -- and in the context of a tremendously entertaining stage show. With local jazz adventurer Byron Morris, Friday and Saturday at Fort Dupont Summer Theatre, and free, to boot. THEATER

When actor Jason Robards and director Jose' Quintero teamed up in 1956 in Eugene O'Neill's "The Iceman Cometh," they made theatrical history. They are likely to do it all over again in the towering revival currently being presented by the American National Theater (in the Eisenhower Theater). The play, nearly five hours long, is a devastating look at a barful of derelicts and the traveling salesman (Robards) who would strip them of their life-sustaining pipe dreams.