One of the more thought-provoking critical observations I've come across lately (Amy Linden's, to be exact) is the claim that the current crop of young black singers could learn something from the 22-year-old singer-songwriter Fiona Apple about soul. That's "soul" as in Soul, as in Gladys and Nina, as in "I Can't Stand the Rain" and "Natural Woman," which, come to think of it, was written by Carole King when she was a skinny white New Yorker just like Apple.

While I watched Apple perform May 8 at Nakano Sun Plaza, it did occur to me that the groaning, wailing, writhing woman onstage had more in common with the classic gospel-influenced black singers of the '60s and early '70s than she did with other white female singer-songwriters in their early 20s who sport pierced navels and celebrate inner demons.

But soulful singing doesn't make her a Soul Singer. And it's not just because of her music, which is difficult to pigeonhole. In Japan, Sony pushed her second album, "When the Pawn . . . etc.," with the ad copy "I am music. The genre is Fiona Apple," which communicates both the uniqueness of her songs and their arty self-consciousness.

It's the self-consciousness that tends to irritate people. Apple's first album, "Tidal," was released in 1996 when she was 19, and for every positive review that mentioned the originality of her tunes and the power of her voice there was a negative one dissing her naive, cliche-ridden lyrics. Both opinions are valid: Even today, the album sounds great as long as you don't pay close attention to the words, which impart emotional disorder in calculated and melodramatic ways.

What isn't valid is the way a lot of critics used this pretentiousness (which is no worse than Sting's) against her, implying that she was too young to know about such things. Apple may over-romanticize her moodiness, but she knows her feelings better than anyone else, and she's straightforward about the way she accumulates personal experience. As she explains in the righteously crazed "A Mistake," "And when the day is done and I look back/the fact is I had fun, fumbling around."

This acting-out is more pronounced in concert, where it's obvious that Apple inhabits her songs fully. Except in terms of her vocals -- growling and wailing through "On the Bound," shouting and barking through "To Your Love" -- she didn't come through physically on the first two songs since she was busy at the piano, pounding away at her beloved bass chords.

When she stood up for "Criminal," however, she got all slinky and twisty, singing as much with her wrists and hips as with her vocal cords. The pretension meter was poised on overload, but her excellent all-male band turned the bluesy arrangement into a perfect siren song, and as the final guitar pattern sauntered over to the Casbah, Apple slipped effortlessly into a belly dance.

If it seems unnecessary to mention that the band was "all-male," it seems very necessary to mention that Apple's songs don't make sense without men. For all her fierce physicality and sexual candor, she's no riot grrl. She doesn't write ironically about shopping malls or what fun it is to be female. Her lyrics need men the way her music needs Matt Chamberlain's potent, complex drumming, to give it weight and structure.

Similarly, outside the shell of the songs she was very much an adolescent girl who still seems overwhelmed by it all. She didn't speak to the audience much, but when she did blurt out an occasional "thank you" or some hasty Japanese, her hands would flutter like a 5-year-old who had to go to the bathroom.

It was not a jarring contrast, however. During "A Mistake," which is about wanting to be naughty, she threw a mock tantrum, and though some might say it was taking the meaning of the song to extremes, it made sense considering how well the arrangement conveyed anger.

The single, "Fast As You Can," didn't make as strong an impression since the melodica was mixed too loud and the switchback changes that give the song its nervous urgency were muddy and unfocused. Reports from the road about the singer falling apart onstage when the sound wasn't right are understandable. She's the perfect singer for her quirky songs, which is why they have to be perfect as well.

It's also why she doesn't always succeed with other people's songs. For an encore, she did Cole Porter's "It Was Just One of Those Things" to a recorded big band accompaniment, and it sounded like amateur karaoke -- flat and overextended.

Then she sang Bill Withers' funky "Kissing My Love," a genuine Soul Number. While the group grooved, she got carried away again, whipping her hair around and moaning like a goat in heat. It was a bit much considering the song's lighthearted sexiness. Apple's intense singing style was developed for her intense compositions, but she hasn't learned how to put over a silly love song yet. It isn't as easy as it sounds. Ask any Soul Singer.