Los Angeles ? Bob Newhart responds with customary modesty when asked about his selection as a subject for the PBS series “American Masters”:

“I don’t think of myself as an American Master,” the 75-year-old says. “I’ve just been making a living. I just thought that (my career) would end in five years.”

But his popularity didn’t end after his smash 1960 comedy album, “The Button-Down Mind of Bob Newhart.” The collection of his monologues, such as “Abe Lincoln vs. Madison Avenue” and “The Nude Police Line-Up,” made him a hot ticket on TV variety shows, in nightclubs and theaters. Then came two hit TV series. Not bad for a guy who used to be an accountant.

“American Masters,” which airs at 8 p.m. today, traces Newhart’s life and career with clips from his TV series and concert appearances, plus comments by his fellow comedians and Newhart himself.

Bob and Virginia Newhart live alone in a chateau deep in plush Bel-Air. Their two sons and two daughters have married and flown the nest; they now have six grandchildren.

The Newhart saga began in his native Chicago, where he had moved from accounting to writing ad copy. A fan of the Bob and Ray comedy team on radio, he collaborated with a friend, Ed Gallagher, on comedy scenes they recorded and sent to radio stations. No sale.

Gallagher moved to New York, and Newhart continued solo. Warner Bros. Records bought his “Button-Down Mind” album, and it zoomed to No. 1 on the charts and won three Grammys, including album of the year.

“There really was a sea change in comedy around the late 1950s and early ’60s,” Newhart remembers. “Shelley Berman, Mike (Nichols) and Elaine (May), Jonathan Winters, Lenny Bruce – it was a departure from what had gone before. There had been ‘Take my wife please’- little vignettes like Henny Youngman’s.

“We didn’t all get together and say, ‘We’ve got to change the face of comedy.’ It was just our way of doing it. We also have to give credit to our audience. You could speak to them on a level, and they would know what you’re talking about.”

The PBS American

Newhart moved to Hollywood in 1961 and starred in a TV variety show. “We got an Emmy, a Peabody and a pink slip from NBC, all in one season,” he says with a rueful smile.

He waited until 1972 before embarking on CBS’ “The Bob Newhart Show,” which became a classic sitcom in its six-season run. Another CBS sitcom, “Newhart,” began in ’82 and lasted eight years. A third series, 1992’s “Bob,” failed in one season.

Even though he left the series grind behind, he’s far from retired. He still manages about 35 appearances per year with his monologues and has played roles in the movies “In & Out,” “Legally Blonde 2: Red, White & Blonde” and “Elf.”

On television, he was impressive in a dramatic role as a suicidal widower on “ER” and on TNT’s movie “The Librarian: Quest for the Spear.” But his most notable recent TV appearances came on two episodes of last season’s hit “Desperate Housewives,” playing the estranged boyfriend of Leslie Ann Warren.

Newhart certainly has other activities to keep him occupied, including writing his autobiography.

“I had hemmed and hawed for years,” he says, “and I finally decided this year I gotta do it. I signed a piece of paper (with Hyperion). That’s what I had to do. I know me. I’d still be on Page One if I hadn’t signed that piece of paper.”