A fan, a young woman, runs up to the edge of the stage as Joni Mitchell collects the roses left for her there Wednesday night and presents her a huge colored sketch, a sketch so big that even the back rows in Shea's Buffalo can see that it's quite a different Joni.

Like an idolized older sister who returns after an extended absence, she's no longer the wide-eyed, straight-haired idealist in the portrait. Hers is a case of advanced sophistication. It's narrowed her gaze, bleached and frizzed her head, put a touch of graininess in her voice and turned her music into something beyond its old haunting sensitivity.

Take the song For Free. Originally the thoughts of a professional moved by the pure art of a street musician, it's now scatted and twisted to the point where it's almost unrecognizable.

It amounts to a translation of her old folk numbers into the jazz in which she immersed herself over the last few years and a realignment of the jazz to fit the format of the four-man rock band backing her up.

She strums a big hollow-bodied cordless electric guitar to start up the first set with the jazzy Coyote, the other instruments falling in behind her on the second verse. The sound mix is a bit uneven, a handicap that becomes more pronounced in the rushed Free Man In Paris that follows.

She says something about summer nights and dance halls and finds her balance in Cotton Avenue as Mike Landau's electric guitar links the jazz lilt and the rock intensity with his fleet-fingered filigree.

From there, the two-part, two-hour concert winds up touching virtually every part of her repertoire, except for the very earliest albums, as she moves from guitar to piano to dulcimer (for A Case of You). God Must Be a Boogie Man spotlights her new husband, Larry Klein, on bass.

The formality of the first half is underscored by Joni's long layered dress and short heels. For the second half, she goes casual in pants. Klein sheds his cap at intermission and comes back, in a football jersey.

The title track of the new album, WILD THINGS RUN FAST, brings them back to the stage on a lively note. These new songs - in all, she does Chinese Cafe, Solid Love, (You're So Square) Baby, I Don't Care, You Dream Flat Tires and Love - are the least altered.

If there's any complaint, it involves the sparseness of this setup, especially after the lush jazz virtuosity of her SHADOWS AND LIGHT TOUR in 1979. No one in the band does harmonies. They're missed. And what about a saxophone? That would increase their dimension considerably.

Also there's surprisingly little interplay between her and Klein on stage. Her cool formula of "fifty-fifty fire and ice" is a bit on the icy side, at least until the encores.

For her first return, she unexpectedly launches into the old Motown hit, I Heard It Through the Grapevine. The ensuing applause brings her back singing a jesting verse of Shuffle Off To Buffalo, followed by a straightforward Underneath the Streetlight from the new album.

Incredibly, she comes back a third time, alone with her cordless guitar to do Woodstock, just as she'd done in 1979. Elated, she goes to the very edge of the stage, strolls' across it, then exits, still playing, as the lights come down. With that, the new portrait is complete.