IT'S HARD TO imagine a pop-music artist who could be more out of fashion at this point than Joni Mitchell: a nakedly honest, introspective folkie who doesn't apologize for noodling around with less-accessible jazz riffs scarcely fits in a landscape filled with hip-hop braggadocio and teen-pop inanity.

But Mitchell's strength was always that she never sought pop stardom, tonight's "American Masters' (memo to PBS: Mitchell is Canadian) notes; that's what kept her music pure, even if no one really wanted to hear it. Writer/director/producer Susan Lacy, who seems to have created a documentary intended most of all to please her subject, suggests that if Mitchell failed fans' expectations, fans likewise failed hers by expecting her to endlessly churn out carbon copies of her hit "Court and Spark.' (Nonetheless, few hard-core music fans have that album, but wouldn't be caught dead without a copy of her earlier recording "Blue').

"Sweet Joni from Saskatchewan,' as Neil Young called her in an unreleased song, grew up a recluse, had a youthful romantic life euphemistically described as "difficult,' yet managed to become a star via her intimate songwriting. Lacy's film combines many early video performances with interviews with many from the '60s singer-songwriter movement, including some of her paramours.

Lacy may gloss over Mitchell's career lulls and profligate romanticism and not quite offer an insightful glimpse into her creative process, but she offers fans plenty of her best music at length, not diced up in the MTV fashion preferred nowadays. "Woman of Heart and Mind' is clearly designed for unquestioning fans, and it might just earn Mitchell a new convert or two.