The very best tribute albums offer new insights into a spotlighted artist or musical period, with recastings that help you hear the material differently and more clearly.

"A Tribute to Joni Mitchell" (Nonesuch, A) is just such a treasure trove, rich with performances that illuminate Mitchell's painterly visions and trouble-in-mind emotions.

With her odd Icelandic accents, Bjork opens up the exotic imagery of "The Boho Dance," while Brazil's Caetano Veloso leads us delicately into the rain forest and samba sway of "Dreamland."

If Prince's "A Case of You," Emmylou Harris' pining over the pregnant penitents of "The Magadalen Laundries" and James Taylor's chilling "River" don't make you cry one, nothing will.

Elsewhere, Elvis Costello dresses up "Edith and the Kingpin" with a high-falutin' chamber orchestra while Sufjan Stevens' wobbly, brass-tuned arrangement of "Free Man in Paris" is even more unsettling and magical.

Other sterling efforts are put forth by jazz pianist Brad Mehldau, Sarah McLachlan, Cassandra Wilson, Annie Lennox and k.d. lang.

While originally conceived as a homage to the gospel rooted "freedom" songs that spirited the Civil Rights movement of the 1950s and '60s, Mavis Staples' "We'll Never Turn Back" (Anti-, A) became so much more.

This edgy, acoustic-minded, Ry Cooder-helmed production has a goosebump-inducing immediacy that makes the music feels very contemporary, personal and important.

As her own contribution (co-authored with Cooder) "My Own Eyes" testifies, Staples and her famous family of singers had their own bouts with racial prejudice. The whole album feels autobiographically constructed, from her childhood "Down In Mississippi" to the family's rallying cries (marching alongside civil rights activist Dr. Martin Luther King Jr.) with "Eye On the Prize" and "We Shall Not Be Moved" to the album's re-assertive title track. Parents and teachers, share this with your kids!

VIOLINS, SWEET VIOLINS: Strings-endowed pop rock is a major trend these days. Some of the sweetest I've heard is found on "Imaginary Kingdom" (EMI, B+) from the Aussie talent Tim Finn - whom you know best from Crowded House. Nature-evoking ballads - "Astounding Moon" and "Winter Light" - are Finn's special forte, though I also felt liberated by rocking motivators like "Midnight Coma."

Classic prog-rock impulses - from the ELO-ish violins and brass-scored "You Will Be Loved" to the 10 CC-ish psychedelic reggae "Wake Up and Live" - make for a fun variety pack from "Future Clouds and Radar" (The Star Apple Kingdom, B+).

Masterminded by Austin, Texas, talent Robert Harrison (ex-Cotton Mather), the ambitions stretch over two discs and 27 tunes, with only a couple of ho-hummers in the midst.

Cowboy Junkies aim for a reflective, chamber pop feel in "At the End of Paths Taken," (Zoe, B). It's a song cycle of birth, life and death proportions by songwriter Michael Timmins, with vocalist wife Margo again setting a haunting tone.

Porcupine Tree strives for the grandeur of Yes and the politics of despair on "Fear of A Blank Planet" (Atlantic, B).

LET'S GO GLOBE HOPPING: On "5:55" (Atlantic, B+), second-generation French popster Charlotte Gainsbourg builds on the breathy, seductive aura of her dad (Serge) and mom (actress Jane Birkin).

But Gainsbourg has smartly modernized the come-ons with techy, persuasive percussion tweaks by her friends in Air, Pulp frontman Jarvis Cocker and The Divine Comedy's Neil Hannon.

Another famous offspring, Bebel Gilberto, actually moves closer to her dad's Brazilian samba roots on "Momento" (Six Degrees, B).

With flutes, fiddles and accordion a-flyin', Scottish charmer Nuala Kennedy takes Celtic instrumental and vocal music from sprightly trad to Django-like jazz on the delightful "The New Shoes" (Compass, A-).

Put on your own dancing shoes before cuing up "Putumayo World Party" (Putumayo, B), a beat-centric mix of zouk, salsa, ska, compas, reggae and zydeco gems.

Buena Vista Social Club's primo vocalist Ibrahim Ferrer bids farewell to this mortal coil with the mellifluous "Mi Sueno" (Nonesuch, B+).

Hurray for Bollywood - that's to say, the exotic, room-spinning, glitz and glam sounds of "The Rough Guide To Bollywood Gold" (Rough Guide, B). *