LOS ANGELES - If any rocker has the right to act like a diva, it's Patti Smith. The Rock and Roll Hall of Famer may not have the musical chops of Chrissie Hynde or Janis Joplin, but her no-surrender approach to music convinced a generation of future punkers that attitude is a musician's most valuable instrument.

In person, however, Smith is about as accessible and relaxed as a Muzak mixer, rehashing war stories from the road with journalists long past happy hour, even though she has just flown in from Japan. That's also the Smith whom viewers will get to know in the documentary Patti Smith: Dream of Life premiering tonight on WHYY TV12. It's an intimate, disarming look at an artist who comes across as the polar opposite of her ferocious onstage character.

Director Steven Sebring, an acclaimed fashion photographer, spent more than a decade capturing his subject in very unglamorous moments: swapping tales with the Red Hot Chili Peppers' Flea about urinating in public, reminiscing with her father at her childhood home about how he used to feed the squirrels, snapping photos at the gravesite of William Blake, lovingly stroking a homemade dress she wore as a child. They're as shocking and sweet as catching Mick Jagger taking out the trash.

Yes, there are some rock-and-roll moments, most notably a primal, passionate indictment of then-president George W. Bush, but those who tune in primarily to hear "Because the Night" will be disappointed.

"This is a much more nuanced portrait of someone in popular culture that, you know, has been pigeonholed as a rock-and-roll icon," said Simon Kilmurry, executive producer for P.O.V., the documentary series that picked up the movie after it won a 2008 cinematography award at the Sundance Film Festival. "But it's a much more complicated artistic life that she leads, and I don't think it would be portrayed in another film."

Smith's contributions to the punk scene are barely acknowledged. Poor saps who have never listened to her 1975 masterpiece, Horses, and think she's most famous for marrying John McEnroe (that's actually Scandal lead singer Patty Smyth) will think she's some glorified groupie, clinging to fading memories of her times with Bob Dylan, photographer Robert Mapplethorpe, and her late husband, MC5 guitarist Fred (Sonic) Smith.

In fact, the most memorable anecdote in the film is Smith talking about how she used to encourage musicians to try out her 1931 Gibson guitar - only because it needed tuning. Sebring also captures a cute, amateurish duet with playwright/actor/former boyfriend Sam Shepard that's akin to a junior-high performance of True West.

What the film fails to address, Smith did in person.

"We were more like the bridge between traditional rock and, well, the punk movement," said the singer, whose roots are in Philadelphia and South Jersey. "We wanted to remind people that rock-and-roll did belong to the people, that it was our cultural voice, and we were trying to move from the glamorous, indulgent aspects of the music in the early '70s. I always sort of thought of us as Moses. We saw the promised land, but it was really the new guard that got there. Except as a guitar player. I'm still as bad and noisy as any punk guitarist out there."