Knock, knock. Who’s there? Paula Cole. Paula Cole who? Even she doesn’t know.

Singer-songwriters of pretty much every stripe have been criticized for their almost cartoonish self-involvement, and Paula Cole--who sings Tuesday at the Coach House--probably isn’t going to change anyone’s mind about that. But she is able to engage in rambling dissertations about herself without coming off as obnoxious or narcissistic--one heck of an achievement.

During a recent phone interview, she made no bones about the fact that she is “really proud of ‘The Fire’,” her second album, released last week. “I really like it. It’s me, and I like me. I feel glad to be who I am in my life and glad to be making this music. I see my albums as working diaries, as living scrapbooks of me and my life.

“I’m still trying to find out who Paula Cole is. I always am--and I always will be--my real, inside self, which has no name.”

The amazing thing is despite all that, she came across as affable, even charming, a person you want to root for. I liked her almost as much as she liked herself.

There is, of course, also the matter of her music: “The Fire” is so good that it helps convince one that perhaps Paula Cole has good reason to be so hung up on Paula Cole.

Her songs are emotional, personal journeys of the search for self. Her voice is a most remarkable instrument that can go from a whisper to a tremulous wail, or a misery-gargling gruffness, in the space of a single song. Her compositions are jazzy and sophisticated yet melodic and accessible.

Cole, 28, grew up in small-town Massachusetts, a member of a musical family that spent a lot of time singing together. “My family was far and away the biggest musical influence in my life,” she said. “We watched hardly any television at all or any other media. In hindsight, I’m lucky. I’m very different, and because of that I’m more self-reliant.”

She attended Berklee College of Music in Boston, where she majored in voice. “I was one of the only white people in the gospel choir, and that was a wonderful experience for this sheltered little white girl from Massachusetts to have.

“That was the good thing about Berklee, the eclectic makeup of the student body. Every color and culture was there. It was wonderful. I’ve always been fascinated by black music, and jazz was a particularly natural step for me. I was curious and hungry at a young age, and jazz was such a mystery to me, an ocean where you can express yourself in the moment. It represented freedom, it represented wearing wings and going somewhere with music.”

Once out of school, she worked as a background vocalist, most notably for Peter Gabriel, with whom she toured for a year, playing Woodstock and performing in the Grammy-winning “Secret World Live” video.

“Just by being there [with Gabriel], observing the entire situation, observing the greatness and the mistakes, I learned a lot,” she said.

After her stint with Gabriel, she was signed by Imago Records and eventually moved to its parent label, Warner Bros. Her debut album, “Harbinger,” was released two years ago.

She said that she feels it is her destiny to have a long and productive career and that she hopes to “raise some consciousness” through her music. But there’s still one more creative itch she feels compelled to explore as well:

“I’d love to act. I feel that it’s another naked, mysterious challenge, like jazz. It kind of intrigues me in the same way. It seems challenging and scary as hell to me. But I’d like to try it.”

* Paula Cole sings Tuesday at the Coach House, 33157 Camino Capistrano, San Juan Capistrano. Walnut Grove opens at 8 p.m. $12.50-$14.50. (714) 496-8930.