"If medicine is his wife and jazz is his mistress, where does that leave me?" asks Janice Eanet, married for 26 years to Dr. Lawrence Eanet, Bethesda dermatologist and a well-known jazz pianist in Washington.

Larry Eanet, 52, shrugs. "I can't live without music!" he cries. "I just can't do it! I started at age 4 and I have been playing professionally since age 14 . . . I'll take any excuse to make music!"

When Eanet plays the piano, his eyes glaze over, his jaw hangs, his head nods, his feet wander the pedals. His energy goes to his fingers. He plays clubs and restaurants all over town--Charlie's Georgetown, Hogate's Seafood Restaurant, the big hotels. His favorite songs are those by songwriters such as George Gershwin and Cole Porter, for instance.

"I am lucky in that I don't have to take any job," Eanet says. "I take the jobs that let me play the kind of music I like.

"When I play jazz I play for myself and for other members of the orchestra. We improvise. It's like dancing together without any choreography . . . The music changes from second to second. It has the tension between the discipline of it and the freedom of it."

Eanet studied English at Harvard University and medicine at George Washington University, but the only time he stopped playing music was during his internship.

"It was a terrible period," recalls his wife. "He was despondent. I realized then-- we had been married only for two years--that music is his religion."

One of the reasons Eanet specialized in dermatology was that it would usually leave his evenings free, without emergencies or evening calls.

"My father was an old- fashioned family doctor," Eanet says. "When you do that kind of work, it's your whole way of life. I had to find a way to be myself--to be a musician--and to be a doctor."

His two careers are "supremely irrelevant to each other," he says, "except that each permits the other. Each uses a different part of me."

Eanet once tried to make a living as a musician. "It was in 1957-58," he says, "and it was terrible. I had to take what came. For one year, I played in neighborhood bars in southwest Chicago. Then I got lucky and played dinner music in a good French restaurant. At least I ate well."

Working nearly 50 hours a week as a doctor and playing as many as five nights a week does take its toll on family life. "But my kids grew up as human beings anyway," he says. All three of them play music. "They didn't catch medicine from me," he says.

Eanet earns much less playing piano than practicing medicine. "But music means more to me," he says.

He earns anywhere from $75 to $200 for an evening of performing. "What I earn from music is mad money-- money I spend when I am crazy," he says. "It's for special things--vacations, presents, indulgences."

Leading two lives, Eanet says, is like climbing halfway over a barbed wire fence. "It's uncomfortable, but it hurts more either to get across or to crawl back. So you stay impaled, one leg on each side."

For many years he was torn between his two interests, but no longer. "I plan to retire from dermatology at the rate of 5 percent a year for 20 years," Eanet says. "Then I'll be 72, and I'll just play music. God willing."