Jhane Barnes was already forceful enough at 17 to order the boys in the band at Dulaney (Md.) High to try on her costumes. The rest was easy: The musicians chucked their clichéd red blazers and black pants in favor of the blue Lurex jumpsuits she ran up on her mother's sewing machine. Nine years later Jhane is fast making her unusual name (she added the "h" in 1977 to set her apart) as one of the few females in the $12 billion menswear industry. Last year, at 25, she won both the Cutty Sark men's fashion prize as most promising designer and a coveted Coty Award. "It's great to see a woman doing so well in this field," bravos Geoffrey Beene. "She's off to a good start," allows John Weitz grudgingly, "but the key to success in menswear is longevity."

Perhaps. But after only five years in business, Barnes has duded out the big names and spun off a distaff line after women began snapping up her small-size men's jackets. Cher and Bette Midler both own her $200 glitter vest (the fabric is a Barnes blend of flannel and Lurex). Elton John shelled out $375 for her Dalmatian jacket in black-and-white-speckled tweed. Robin (Mork) Williams chose Barnes' off-white ribbon jacket ($385). And onstage, Daryl Hall and John Oates perform in her $180 purple glitter pants. Barnes' most enthusiastic peacock is probably Richard Dreyfuss. Last fall he stockpiled six of her jackets.

The prices apparently are no deterrent. Barnes' trousers begin at $110, her jackets fetch between $350 and $550, sweaters $130 to $250. With outlets in Neiman-Marcus, I. Magnin and Saks Fifth Avenue and specialty stores like San Francisco's Wilkes Bashford, Barnes grossed $2 million last year and expects to ring up $3.5 million in 1981.

Adopted as a baby by a now retired banker and an ex-schoolmarm, Jhane grew up 30 miles from Baltimore. She competed in horse shows until she was 13 and her attention turned elsewhere. "I was boy-crazy," she admits. After high school she moved to New York and enrolled at the Fashion Institute of Technology. "I decided menswear needed a lift," she says, and in her final semester launched her first fashion show, which led to a flood of calls from department store buyers. "I pretended I had a company," giggles Jhane, "and gave them my address in Brooklyn. I slept under my cutting table at night and took all the cut garments by subway to the Manhattan factory."

Barnes was soon earning high marks for her custom-designed fabrics. She still hand-dyes yarns and weaves samples, which two mills in Rhode Island meticulously reproduce for her. Her spring '81 line features lots of pinks and purples, plus offbeat hues like "brownish melon" and "julep green." Equally finicky about tailoring, she is currently improvising on the baseball warm-up jacket. As for men's pants, Barnes believes, "Girls watch, but they don't want to see a bulge in the front. A rounded seat—that's more civilized."

Jhane lives alone in a two-bedroom flat on Manhattan's East Side, but spends many nights in her midtown workroom with her alley cat, Puppy. It all seemed worthwhile, however, when she learned that on a recent shopping spree several gents had tried to wriggle into her ribbon and glitter jackets. But to no avail—the armholes were cut too small. At least Jhane had the satisfaction of knowing that admirers of her seemingly effete design include three Pittsburgh Steeler linemen.