At 79, with some of the greatest works of American musical theatre to his credit, Stephen So­n­dheim has reached that point in a prolific composer’s career when major revivals of his shows now number in the double digits. And with revival has come reconception. On Broadway the most evident trend has been toward chamber-style orchestrations like the eight-instrument arrangements for the current revival of “A Little Night Music,” Sondheim and Hugh Wheeler’s story of aging lovers grappling with regrets.

The chamberisation of his work has had a double-edged, somewhat surreal eff­ect on him, Sondheim sa­id during a recent interview at his Manhattan house.

“I’ve reached an age where I’m two generations past when I was considered avant-garde. I went right from avant-garde to being old hat in five minutes, and you start to feel superannuated,” he said. “With every new generation, popular art changes. Already there’s a generation that thinks the Beatles are old-fashioned, which I find screamingly funny. The same thing is true of plays and musicals. People need things loud and fast. That’s one of the things that I like about ‘Little Night Music.’ The musical says: Slow down. Slow down and think.”

A part of him misses “the big swells from larger orchestras” absent from the current “Night Music,” at the Walter Kerr Theater, as well as the musically pared-down Broadway revivals of “Sweeney Todd” (2005) and “Sunday in the Park With George” (2008). It is strange, he said, to imagine that new generations of theatergoers might first experience his work on an intimate scale rather than the lush musicality of the original Broadway productions decades ago.

And yet for an artist long admired for breaking new ground with composition form and incisive, nuanced lyrics, the new approach has also been stimulating. While he is now completing a two-volume book on theatre and lyric writing, Sondheim said, he is not content simply to be a custodian for his shows or fly all over the world putting seals of approval on directors’ rethinking of his works.

“The good news from this chamber approach is that you get to concentrate on the piece of work rather than on the production,” said Sondheim, who also includes the scaled-down Broadway revival of “Company” (2006) in the recent trend. (In “Company” and “Sweeney Todd,” both directed by John Doyle, the actors played the instruments.)

In an era of blockbuster musicals, rock-oriented shows like the forthcoming “American Idiot” and reality television that turns musical performance into “American Idol” contests, Sondheim said that he bristled — “chills go up my spine” — whenever he hears someone say that a certain musical form is timely or relevant. For him the goal has always been telling a strong, clear story.