In the early days of the glamor conscious 70s, layered, blown dry hair styles swept locks across sexual and racial lines.

The look became the crown of fashionable heads throughout the decade, and demand for it created a new phenomenon in the black hair care business.

Where women had once gone to small, crowded neighborhood beauty parlors for the traditional marcel, the new freedom of the blown dry style, coupled with a new widespread readiness to pay for it, encouraged chic salons of mirrors and music.

When Shelton Williams opened Shelton's Hair Gallery at 1758 Columbia Rd. NW in 1974, it became one of a handful of such salons for a predominantly black clientele. Last year he opened another shop, all plants, music, chrome and mirrors, this time in the heart of the downtown fashion district, at 1215 Connecticut Ave. NW.

Williams was studying economics in graduate school at Howard University, and cutting hair parttime in a salon on Columbia Road when, after being turned down for a raise twice, he decided to open his own business.

His customers tend to be "young, black middle class men and women who recognize the importance of hair as a part of a total look," Williams explains.

Several of the Washington Redskins and their wives are among his regulars. Actress Berlinda Tolbert of "the Jeffersons" television series visited the salon during a recent trip to Washington, he said.

Williams says the first step toward pleasing his customers is to make them aware of the possibilities and limitations of their hair.

"The best way to get a person to trust you is not to argue with them, but to show them that you know what you're doing by first showing them exactly what they have to work with," he says.

"I have people coming in all the time saying, 'Make me look like that.'" He points to a display card of a striking model with honey-brown hair draped to one side.

"I say okay, then hand them a mirror and while they look at themselves, I explain just how her hair came to look that way." He said he doesn't begin to work on a customer's hair until they agree on what is realistic.

Though 95 percent of his customers are black, Williams says it's difficult to categorize "black" hair.

"The problem with defining 'black' hair is that it covers a wide spectrum. It goes from super straight to super knotty. My staff (a 22-person, multi-racial, male and female group) is trained to work with all types of hair," he said. But to illustrate some of the special needs of black hair, Williams divides black hair into three categories: tight and kinky; loose, soft hair that "goes straight," and curly.

Of the three, Williams says that curly hair is the most difficult to work with. "Although curly hair has nice wave patterns to it, it stretches and is hard to control."

The worst hair problems develop, he cautioned, when people change their hair from kinky to straight.

"Once virgin hair (hair that has never been chemically treated) is chemically straightened, the upkeep is a must." The trouble is that most people have serious misconceptions about what chemical relaxers do to hair, he said.

"Believe it or not, most chemicals do the exact opposite of what you probably think they do. A mild relaxer will not straighten curly hair. The curlier the hair, the stronger a relaxer you will need. The kinkier hair is porous, which is why it needs conditioners that seal in moisture and vitamins."

Shelton's Hair Galleries, aside from offering the usual eyebrow, makeup, manicure and pedicure treatments people have come to expect from such salons, also offer cornrowing and hairweaving. Dropping $100 in one afternoon is commonplace around his shops, but Shelton easily remembered the most any customer had spent. She was the one who returned every day for three days in the course of getting a hairweave. When it was over, she got and paid, the highest bill yet, $625.