Joni Mitchell doesn't surface too often in media-covered social circles, but when she does you can bet it's a big deal.

Witness the bash Monday night at the James Corcoran Gallery, where songstress Mitchell introduced her new album, "Dog Eat Dog" (her first since "Wild Things Run Fast"in 1982) and the start of a three-day exhibition of her paintings that ends today. The party was given by the gallery and Geffen Records (her label); proceeds from ticket sales went to the Museum of Contemporary Art.

Upon entering, guests were given a lyric sheet, and when they left they got an album. Some of the music was piped into one of the rooms of the gallery, but a steady din of chatter drowned it out.

It seemed all of West Hollywood pressed into the gallery for a chance to glimpse Mitchell or some of the other famous people who showed up: Jack Nicholson, Toni Basil, Sheena Easton, Jane Wiedlin, Gale Hayman with a nervous Stephen Sprouse, Christopher Cross, Mary Woronov, Bill Graham, Penny Marshall, record producer Peter Asher, Joan Quinn, Peter Alexander, Shelley Duvall, Wallis Annenberg with John Gerace, and founding trustee of MoCA Marcia Weisman, who said, "There are three winners here tonight: Joni Mitchell, James Corcoran and the Museum of Contemporary Art.

It wasn't unusual to see Mitchell surrounded at most times by a crowd three-deep. And when she showed how one of her paintings could be changed if she moved pieces of canvas around, photographers went nuts. "This is like Barbie dolls,"she said.

It took us a good hour before we were granted some time alone with Mitchell, who was wearing a beret with her Issey Miyake dress. (A conversation Mitchell had with Joan Quinn revealed that they were both wearing creations by the avant-garde Japanese designer. "No one understands it but us," Mitchell said.)

She became involved with MoCA through Wendy Stark (daughter of producer Ray), who is a friend. "She collects art, and she was watching this stuff stack up. Wendy talked to Marcia Weisman and set this up. From there I had my choice of a few galleries, and I like the way Jim buys. I like the things he had in here when I saw it."

There is an evolution in the work that was hanging in the gallery - - one of the paintings completed just days ago has a "style that is freer. I have a studio now, and I no longer have to worry about dripping paint on the floor."

So far the album has received two rave reviews, and radio stations are airing it - - sometimes several cuts at a time.

"The album is more mainstream: she said. "It just happened naturally. I change according to what I like and what I listen to. I'm more intuitive - - it's less of a conscious decision."