Imagine Garth Brooks in a shag haircut and leopard-print spandex pants. Or Kurt Cobain of Nirvana in one of Garth's black hats. How about the En Vogue girls in plaid flannel shirts and slashed blue jeans?

Impossible. These musicians, along with their MTV peers, are known as much for their carefully cultivated fashion sensibilities as their musical styles. And behind nearly every successful band a stylist works to orchestrate the right look.

Stylists' contributions to a performer's success may be ignored at Grammy time (Feb. 24), but their importance is recognized in the music business.

"It is not unusual for production and talent companies to invest up to five or six figures in an artist before they are marketed to the world," says Cleveland O'Neil, owner of a talent management agency. "The more packaged an act is in terms of style and identity the easier it is for a record company to market the act."

En Vogue is a packaged act, says O'Neil. And their success prompted him to put together his own all-girl, a cappella group, Mix Match. The three California teens were signed last fall, their stage style was created in December and, if all goes according to schedule, O'Neil expects a record contract by the end of March.

O'Neil called a stylist before he rang up the record companies because looks are crucial to a band's success. An inadequate performance can be adjusted on a mixing board. It is left to the stylist to tell an artist that his rat's-nest hair or 20 extra pounds have to go. Stylists must forge a connection with the performer to deal with such sensitive issues.

"I have to like the person and love the music to be able to do what I do," says Arianne Phillips, who dresses Lenny Kravitz, Vanessa Paradis and a new band called Charles and Eddy.

What she does often causes waves. Four years ago, Phillips, 29, put Kravitz in bell-bottoms and a disco top for the American Music Awards. She says she received hate calls and a lot of flak from industry people who thought she had gone too far.

Now that bell-bottoms are a hot item, she feels vindicated. Kravitz, she says, never wavered in his support of her choices, and the two still shop together.

More difficult than putting together stage clothes, says Phillips, is dressing musicians for the cover of Rolling Stone. Because an appearance there is considered a hallmark of success, artists tend to be cautious about what they wear, she says. But Phillips tries to persuade them to push the envelope. "As a stylist, that is what I can do to help illustrate what they are about."