Marvin Hamlisch looks like a cross between a CPA and an opthalmologist. He has a physique akin to Tiny Tim's -- suggesting he ate too many jelly donuts when he was a kid -- a pasty face and an insatiable interest in himself. But he was also given a big, fat gift.

He can write beautiful music and, on occasion, has.

For the premiere of the new public TV version of "Camera Three," Sunday night at 7 on Channel 26, Hamlisch obligingly talks about himself, his talent and his craft. This makes a surprisingly genial and gratifying half hour, one that opens and closes with the most affecting wistful melody to come out of the '70s, Hamlisch's theme to "The Way We Were."

In between way-we-weres, there are glimpses of less celebrated Hamlisch film scores, including "The Swimmer" and a portion of the sardonically sensuous main titles for "The Spy Who Loved Me." And Candice Bergen can be seen rehearsing the theme for the current film comedy "Starting Over," with Hamlisch coaching her.

The program also offers a compact education in the mechanics of film scoring, as Hamlisch explains the 'click track" used by many movie composers, shows how music is applied to a scene, and demonstrates how 16 tracks of sound are mixed down to three. Hamlisch's friends Joel Grey and Carole Bayer Sager, the lyricist, talk about their celebrated pal.

But the bulk of the program consists of Hamlisch holding forth from a piano, slouched in abysmal posture as he waxes alternately introspective, self-defensive and just plain hammy. He's a show biz baby, given to multiple uses of "terrific" and "like, wow" and a compulsion to perform.

He isn't satisfied with his role as prolific composer, any more than he is satisfied with the notices his score for the Broadway show "A Chorus Line" received. "What I had written I thought was really rather terrific, really," he says. The thing is, really, he's right.

For 25 years, "Camera Three" was a quiet but persistently diverting fixture each Sunday on the CBS Television Network, though for many of those years the program was preempted in Washington -- callously, almost belligerently -- by the management of what was then WTOP-TV.

The move to public television will bring many of the old CBS shows out of the vault and back to the air and include new productions, like the profile of Marvin Hamlisch, which was impeccably directed by the program's executive producer, John Musilli. In the mythical kingdom of Televisioniana, he is a knight in shing armor.