To his fans in Spokane, Wash., Billy Tipton was a jazzman extraordinaire, a gifted pianist and saxophonist who had played with such luminaries as Jack Teagarden and Russ Carlyle before forming his own popular trio in the 1950s. To friends and neighbors, he was a true family man, a loving husband and devoted father of three adopted sons. "A perfect gentleman" is how Dave Sobol, his longtime friend and agent remembers him. But after the aged and ailing Tipton died at home late last month of bleeding ulcers, he was found to be not quite the perfect gentleman. In fact, he was a woman.

The revelation left Tipton's children both bereaved and, to put it mildly, bewildered. Neither Jon Clark, 26, nor his brothers, Scott also 26, and Billy Jr., 19, had ever suspected their father was female. The news also stunned most residents of the quiet northwestern city. "I couldn't sleep for two days," says Sobol. "For 40 years I knew Billy as a man, and now he's a woman." Meantime, the one woman who could shed light on the mystery—Kitty Oakes, 60ish, the woman Tipton claimed to have married in the early '60s—refused to talk about their life together. Her silence left many people searching for an explanation of just how and why Tipton, who never underwent a sex-change operation, pulled off her astonishing masquerade for the past 50 years.

By her own account, Tipton was born 69 years ago in Oklahoma City (her family, however, believes she was 74 when she died), began giving concerts on the violin at 7 and later studied music in Kansas City. By the time she was 16, when the Big Band era was in full swing, she longed to be a jazz musician, and it was then, Oakes has said, that Tipton began appearing as a man in the hopes that that would boost her chances for success. But to some of Billy's colleagues, that explanation didn't wash. "I don't think there was that kind of prejudice back then," says Red Kelly, a former member of the Woody Herman band. "There weren't a lot of women, but there were plenty that were good and highly respected."

Billy's talent won her plenty of acclaim. During the '30s and '40s, she crisscrossed the country playing Dixieland piano for a host of legendary bands. "Billy was good, real good," says Vince DeBari, a trumpet player during the Big Band era. The Tipton trio was formed in 1954, and the highly popular group enjoyed solid bookings for the next 10 years. They performed at nightclubs, Holiday Inns and Las Vegas-style floor shows throughout the West, serving up a mixture of lounge music, slapstick routines and costumed camp: In one act, Billy donned a bonnet and the trio launched into Ella Fitzgerald's "A-Tisket A-Tasket."

To fellow musicians, Tipton was easy to get to know and sensitive to other people's feelings. However, she rarely talked about her own problems. Though Billy was petite—just 5'4"—with wide hips, perennially pink-cheeked and baby-faced, and had a high singing voice, no one questioned her gender in Spokane, where she settled in 1958 and where the trio got a regular gig at a local nightclub, sharing the stage with strippers and female impersonators. After all, she was involved with a dark-haired beauty named Mary Ann—until Billy was smitten with Kitty Oakes, a buxom, red-haired exotic dancer whom she met in 1960.

Within a few years, the couple had adopted the three boys, and Billy became a near-perfect father. Though not athletic, she played ball, took them camping and repaired their bikes. But there were things Billy studiously avoided. She never swam nor exposed herself in front of the children. "Dad always wore a T-shirt and a belt with an [athletic] cup on the outside of his underwear," recalls Scott. Despite the straight razor in the bathroom, Billy rarely shaved. And she and Kitty had separate bedrooms. "We were told Kitty liked to stay up late," says Jon.

But by 1979 the family had fallen apart. Scott and Jon, who quarreled incessantly with Kitty, moved out. A few months later so did Billy, who moved into a mobile home and eventually brought all her sons under a single roof again. More than anything, it seemed that fatherhood was Billy's greatest joy. "He was always there for me," says Jon, who was almost killed in a motorcycle accident in 1981. "If it wasn't for my dad, I wouldn't have made it. The doctors wanted to amputate my leg, and Dad made them work to save it. He was there every day for the six months I was in the hospital."

Billy's last years were grim; bursitis and arthritis had ended her musical career in 1973, and her once lucrative work as a booking agent brought only a meager income. Since there were no last-minute declarations, no letters of explanation, her sons can never really know Billy's reasons for her concealment—or the cost to her. "He looked worn out and ragged at the end," says Jon. "He got tired of keeping that secret. That's what probably gave him the ulcers and killed him."

Ironically, Billy could have spared herself and her sons a measure of pain. "I think he probably never told us because he was afraid we might have rejected him," says Scott. "I could have accepted it. He did a helluva good job with us. That's what mattered. He was my dad."

—Paula Chin, and Nick Gallo in Spokane