Jule Styne, Betty Comden and Adolph Green, whose last involvement with "Peter Pan" dates back 25 years, have been working on fresh revisions as the revival winds up its run in Washington.

A new Styne-Comden-Green song for star Sandy Ducan will be added either this weekend or when the show arrives in New York, according to a Kennedy Center spokesman. The song will replace the elaborate mermaid dance that currently concludes Act Two.

Styne, Comden and Green, who attended the opening here, were enthusiastic but also full of ideas for changes when they talked to producer Zev Bufman afterward. So Bufman invited them to put a few of those ideas into effect.

Raymond Hardie, the Irish Actor who starred in the original Dublin production of Steward Parker's "Spokesong," will also star in the Olney Theater version, which gets official underway Tuesday night.

Set in Belfast, this add play is about a visionary bicycle merchant who talks (and occasionally sings) to his bikes, which he regards as the cure to most of civilization's not to mention Northern Ireland's problems. There are flashbacks, too, to the equally nutty career of his grandfather, who was running the same shop half a century ago. $"Spokesong" has a part for a unicyclist, and Max Wright, who will play it, has undertaken a crash course in unicycle-riding. "He's got a lot of confidence," says on Olney colleague. "He doesn't thing about falling too much.

Theatre of Sorts, a non-profit company previously known as Earth Onion Women's Theatre, will conduct all series of weekend theater retreats this month. Call 462-6396 for information.

The Sylvia Toond Acting Repertory, an improvisational acting group, that has been working in various federal buildings under the Living Building program, will perform Thursday, Friday and Saturday nights this month at the Irish Times bar, 14 F St.NW.