When the writer Jack Larson was in his 30s, he received the first grant the Rockefeller Foundation ever awarded to a playwright. But that's not what he will be remem bered for.

His elegant, fanciful plays, written mostly in rhymed verse, have been presented in theaters from the Mark Taper Forum in Los Angeles, his hometown, to the Edinburgh Festival Theater in Scotland. He also wrote the libretto for Virgil Thomson's opera "Lord Byron." And in another turn of career, he was associate producer on films like "The Paper Chase," "Urban Cowboy" and "The China Syndrome."But even these endeavors are a mere blip on the radar screen of public attention in comparison with the true source of his lasting fame: in the 1950s, he played Jimmy Olsen, cub reporter for The Daily Planet, on "The Adventures of Superman," a television series that continues in syndication.

Larson is an icon of American popular culture. The bow tie he wore as Jimmy Olsen is on display at the Smithsonian Institution in Washington. He still gets fan mail and is stopped on the street by strangers.

But Larson's latest work is another literary project. He has written the text for a chamber opera with narrator, "The Astronaut's Tale," with a score by the composer Charles Fussell. The work will receive its premiere on Sunday evening in Boston, with Larson as narrator.

Larson has spent his life shuttling back and forth between the world of arts and letters and the world of pop culture. At 65, he still has Jimmy Olsen's impish smile and close-cropped, though now gray, hair. As his friend, the actress Debra Winger has put it, "Jack still has a lot of `golly gee' in him."

Larson regards Jimmy Olsen as his doppelganger. "I've shared my life with him since I was quite young," he said recently. "And now, I see that Jimmy has been very good to me, and I've been very good to him."

It wasn't always that way. Larson never wanted the role, accepted it reluctantly and was dismayed by his success.

At a special school for youths with creative talent, teachers fostered Larson's love of reading and introduced him to Shakespeare. Later, he attended junior college. An agent from Warner Brothers spotted him and signed him up in the same week as Debbie Reynolds. He was 17.

At the studio, Larson was cast in "mostly forgettable" films, he said. His dream was to go to New York and become a playwright and theater actor. A sympathetic agent suggested a way for him to do it.

"It was a one-shot deal, a show for kids, and my agent told me that it didn't have a sponsor and would probably never be broadcast,"

Larson said. "They wanted me to film 26 episodes."

The show, of course, was "Superman." This was 1951.

In 1952, "Superman" found a sponsor and was broadcast to enormous success. And even more than Superman, it was Jimmy - the adolescent Everyman who was always getting himself and Lois Lane ensnared in perilous mix-ups - whom Americans took to heart.

"I thought I would be typecast as an actor, and ruined forever as a writer," Larson said. But needing the work, he played Jimmy for nearly seven seasons, until George Reeves, who portrayed Superman, died, apparently by suicide.

The idea for "The Astronaut's Tale" came to Larson over 20 years ago, when he wrote a new version of the text for Stravinsky's "Histoire du Soldat," which was performed by members of the Los Angeles Philharmonic.

Lately, Larson has been making surprise comebacks as Jimmy Ol-sen on television. Jerry Seinfeld, a huge fan, asked him to make a cameo appearance in an American Express commercial. In 1996, Larson played Olsen for an episode of "Lois and Clark."