"IT'S LIKE having two wives," says Julian Bream, who plays both the guitar and the lute -- though not lately. "The guitar was my first love, and that always has a special quality -- not so profound, but more direct. When I feel like improvising, I always improvise on the guitar, never on the lute. It's as natural to me as breathing."

For the moment, after taking a six-month leave of absence from public performance -- the first sabbatical in his long career -- Bream at 47 is concentrating on his first love, to the total exclusion of the second. When he comes onstage in the Kennedy Center Concert Hall tonight, he will not be carrying the lute with which he usually opens his programs.

"It's a separation but not a divorce," he explains. "One wife was demanding a little more attention. So I decided to put the lute aside for a year or so and play only the guitar. I'll be back to the lute eventually. Next year, I plan to spend about three months with it exclusively."

For places like the Kennedy Center, the guitar is easier than the lute, although neither instrument is really designed for a large, modern concert hall. "It's a very intimate instrument," Bream says, "and I suppose I should be playing in smaller places, but to some extent the audience dictates the size of the hall."

If the guitar is difficult in a large hall, he says, the lute is "almost impossible." But he refuses to use microphones and amplification as some other guitarists do. "Segovia said some time ago that I use amplification, but he must have been thinking of someone else," Bream said. "I never do. I feel that most people listen to canned music out of loudspeakers about 95 percent of the time, and if you can give them the real thing, why not do it? The softness of the sound is good for people. It makes them listen, concentrate and participate rather than having the music thunder at them."

This is a long way from the beginning of his professional career, in the early 1950s, when he played electric guitar in a British dance band. "Actually, it was an Army dance band," he recalls. "When I was 18, I went into the army as a payroll clerk because otherwise I was headed for Korea. Then the opportunity came along to play electric guitar with an Army dance band three nights a week. It was a big band, with five saxes and six brass, and we had a good small group in the rhythm section who would play alone once in a while to give the reeds and brass a rest. That's when I learned the job of improvisation -- a way of making music that is almost totally closed, these days, to the classical performer.

"I kept my career going in the Army while I began to free-lance in London. It was illegal, strictly speaking, but it went unnoticed, and what the eye doesn't see the heart doesn't grieve over."

The life of a London free-lance musician is one of the busiest and most varied in the world, and has produced some of the world's leading soloists, as well as a large corps of skilled, versatile orchestral musicians. With four internationally known orchestras and an enormous amount of recording activity, plus busy opera, ballet and musical comedy seasons, it offers a rich choice of assignments for a talented musician -- and offered even more in the hyperactive early years of the LP era. A musician playing in an orchestra at night might be working on a soundtrack recording in the morning, performing chamber music in the afternoon and sitting in on a jazz session after the evening's classical concert. Julian Bream was one of the international star soloists who emerged from this frenzied and varied activity, along with French horn virtuoso Barry Tuckwell, cellist Jacqueline DuPre, clarinetist Gervase de Peyer and many others. Bream's career exemplifies the versatility of the London freelance, with a repertoire ranging through all the centuries from the Elizabethan period to the present -- including music composed for him by such eminent contemporaries as Benjamin Britten, Heinz Werner Henze, Peter Maxwell Davies and Michael Tippett.Much of his early reputation in the '50s was made on records -- a medium specially suited to the soft-voiced instruments he plays. He has made about three dozen recordings for RCA, two-thirds of them on guitar -- about the same number as Segovia or Narcisco Ypes. From the British Army pay which was his standard at the beginning of his career, his fee has risen to $7,500 per performance. This is a bit less than a star violinist or pianist might claim, probably reflecting the fact that guitar and lute are more suitable to relatively small halls.

The guitar -- even the electric guitar -- came naturally to Bream because his father was an amateur jazz guitarist. "He could hardly read music, but he was very enthusiastic," Bream recalls. "There was always a guitar around the house -- always the sound of a guitar, including guitar records. I was entranced by Django Reinhart -- he was my hero in those days and, I must confess, even in these. Then my father brought home a record of Segovia and he became my second hero, as he still is today.

"My father played one of the first electric guitars in England. He built his own in 1940, because you couldn't buy them in those days. He used three telephone pickups under the strings, which gave chronic distortion on chords but was quite good on single notes."

Bream's formal music studies as a child were on the piano. "You couldn't get a classical guitar teacher in those days," he recalls, "and during the war it was difficult to get a guitar or new strings. My father started me off on the guitar, and we learned classical guitar together."

Later, when he began to be interested in the lute, he had the same problems, only more so. "It was impossible to find a good lute at the beginning of the '50s, as it was to find a good guitar during the war. There were no teachers, so I taught myself, and there was not much music to study outside of museums. I learned to read the Elizabethan lute tablature, which is primitive but easy to learn: Instead of setting down the notes of the composition, it tells you where to pur your fingers."

He was particularly attracted to the lute music of John Dowland, and to Elizabethan lute music in general. "I think Englishmen or Northern Europeans in general are more naturally attracted to the lute than to the guitar, which always seems Spanish exotic -- to our ears. My own style on the guitar grew out of my experience with the lute. I suppose some people might say I play each like the other. And of course I know a lot of guitar fans who wish I would stop playing the lute and vice versa."

Segovia had already established a large, international audience for the guitar before Bream began his career, but Bream pioneered the building of a mass audience for the lute, and during his career the guitar audience has grown explosively. All tickets were sold more than a week ago for his Kennedy Center appearance tonight. Asked how he explains this mass appeal, he looks pleased but puzzled. "I'm not sure, really," he says. "Of course, I enjoy having a large audience, but I don't do anything sepcial to attract them -- in the selection of repertoire, for example. I play what I like and hope that others will enjoy it -- but if they don't, it doesn't worry me much. I'm really playing for myself and inviting or allowing others to listen. That's the kind of instrument the guitar is."