Joni Mitchell is one of the few artists today worthy of Duke Ellington's words of praise: She's beyond category. She's usually filed under pop, and the unaware still call her a folk singer, but her music is closer to jazz, the rhythms and chordal structures-and lyrics- of her songs too sophisticated for the radio- programmer mind.

So Mitchell has been out of the mainstream since she was "stoking the starmaking machinery behind the popular song" on 1974's Court and Spark, her last album to connect with a mass audience. But as her followers know, she's still remarkable.

Taming the Tiger won't appeal to every taste. It's sometimes didactic and probably less musically accessible than 1994's Turbulent Indigo. But its 11 songs are inventive, quirky and utterly uncliched. Lyrically, she covers a lot of ground (perhaps too much), from the world's violence and greed in No Apologies to her mother's condemnation of her for living with her boyfriend in FaceLift. Then there's the title cut's slam on a music industry that produces "formula music…genuine junk food for juveniles."

No purveyor of junk food, Mitchell may not always succeed but deserves credit for stretching in an age of safe rebellion and market-tested innovation.