Both Itzhak Perlman's hands are busy with his crutches as he comes on stage slowly, pauses, smiles at the wild applause, and sits down in front of the National Symphony Orchestra. Concertmaster Miran Kojian has already walked in with two Stradivarius violins -- his own and the soloist's. Once seated, Perlman takes the violin, checks carefully to be sure it is his own (once, in the Kennedy Center Concert Hall, it wasn't) and checks the tuning.

"At the beginning of my career," Perlman says, "the critics always mentioned my disability -- the headlines would say something like 'Crippled Violinist Plays Concerto' -- and that made me mad. Now, they never mention it and I want them to. I think it is important to identify myself not only as a violinist but as one who has a disability."

Perlman has been disabled longer than he has been a violinist, but he has been both for nearly all his life. He caught polio when he was a child of 4 in Tel Aviv and began to study the violin a year later. Now, at 35, he is widely acclaimed as one of the world's leading violinists, and he has been heaped with honors -- including four Grammys this year alone. His appearances must be booked at least two years in advance, and if he chose he could be booked 10 years ahead.

He is also one of the most prestigious spokesmen for the disabled since Helen Keller. As a member of the United Nations committee for the International Year of Disabled Persons, he has become a militant for the cause. "I spend hours on long-distance phone calls," he says, "telling architects about how to design barrier-free buildings. I have begun refusing to play in some halls because of access problems -- for the audience or for me."

But relaxing in his home -- a fortress-like apartment building on New York's Riverside Drive -- he seems one of the happiest people in the world.

Perlman sits in his spacious, child-filled apartment, which was once the home of Babe Ruth. He has closed the glass-paneled French doors of his music room to shut out some of the circumambient noise and settled into a comfortable sofa. Elsewhere in the apartment, Toby, his wife of 14 years, is busy with their four children. Outside in the hall, a small, blond boy is zipping around on a tricycle. A slightly older child comes up to the glass door, rattles the knob, finds it locked, and stands for a while looking in.

"That one's not mine," Perlman says. "It's our day to host the kiddie play group. Sometimes they meet here, sometimes somewhere else -- four or five of them. When they're here, you know it . . ."

Perlman, who was in Washington on March 8 for Itzhak Perlman Day and will return Saturday night for the gala at Ford's Theatre, spends as much time as he can in the New York apartment -- an amazing amount of time for an international star performer.

"I spend approximately nine or 10 months each year traveling," he says. "That doesn't mean I'm away from here the whole time, but I have no solid vacation time during that period. I spend as little time as possible on the road. When I do concerts on the East Coast -- Baltimore, Philadelphia, Boston or Washington -- I don't consider that a tour. It's a long commute. I know all the late airline schedules, and if I can get back to New York after a concert, I do. And now, with the Concorde, I'm beginning to think of London and Paris as commutes."

Even if he can consider the whole world a mere day hop from Riverside Drive, Perlman still has the special problems of a home-loving barnstorming virtuoso -- problems like having his life programmed years ahead. "Right now," he says, "I'm supposed to be guessing how I will feel around Feb. 4, 1983. Will I feel like playing? That's not something I can decide on Feb. 3, 1983."

The music is the slow movement of Beethoven's Violin Concerto, a melody of melancholy recollected in serenity. Perlman sits in front of the NSO -- he is the only virtuoso violinist who performs concertos sitting down. His left hand moves along the neck of his violin, leaping from one position to the next, pausing over a long-held note, trembling to produce the small nuances and fluctuations of tone that make the instrument uniquely expressive. His face shows rapture, like the ecstatic saints in a Renaissance painting. He produces a sound that one hardly expects to hear this side of heaven.

"The violin is a klutz instrument," says Perlman in his apartment. "You clutch it with your chin and shoulder, and as soon as you begin to do that, your back starts to hurt. Some players get a terrible rash on their neck or chin from holding the violin. So, you try to make yourself as comfortable as possible and get to work on the instrument. But first you have to learn how to control your hands, your arms, your fingers, how to stand, what to do with your elbows.

"Then you start in on tone, vibrato, which way the bow is going. Fiddle players have a tough time and a longer time before they can get results. It may be 10 to 15 years before a violinist can get all these things under control and learn how to get what he wants out of the instrument. Then he can start thinking about the music. A pianist's musical responsibility comes much sooner: Once you learn the notes on a piano, you have to start making music. This may explain why there are so many more pianists than violinists. Of course, as a fiddler, I shouldn't complain about that."

Perlman was drawn to the violin when he was 3 1/2 years old. "I was first attracted by the instrument's sound, which still attracts me. The first time I picked up a violin, I wanted to sound like Heifetz immediately, and it was months before I could manage that."

He is joking, of course; Perlman jokes a lot -- even about his disability. Ask him if he has any unfulfilled ambitions, and he is apt to say: "Yes, I would like to play center for the Knicks. The trouble is I'm to short and I have a problem with my knees -- but a lot of basketball players have problems with their knees."

He began seriously studying the violin when he was 5, after his polio had lapsed from a crisis into a permanent disability. "Even after I caught polio," he says, "there was never any question of my starting the violin at 5. Fortunately, my parents' whole attitude was: 'You can do it.' Like a lot of Jewish kids, I was brought up with this automatic expectation: 'My son is going to play the violin.' My parents did the right thing totally from intinct."

He recalls that "it took me a year or two to get a good sound -- I mean one that you could stand, a sound that would not make you want to throw things at me or run out of the room. People started to say I had a nice tone when I was about 9 or 10." He gave his first public performance in Tel Aviv when he was 9, moved to New York at 13 to study at the Juilliard School, played in Carnegie Hall when he was 18 and won the prestigious Leventritt a year later, in 1964. Since then, it has been an international star career.

"Your repertoire tends to change as you go along," he says. "You begin as a promising young talent and you play things that will make a strong impression immediately -- things like the Paganini, Sibelius and Tchaikovsky concertos. Then when the promise starts to be fulfilled, you are allowed to play Brahms. You really begin to feel better about yourself when requests start coming in for the Beethoven. Then, an occasional request for a Mozart concerto arrives and you know you've really made it. Actually, though, I'm keeping up the old repertoire. I'm doing Paganini and Tcaikovsky this season."

Since winning his Leventritt 17 years ago, Perlman has played these concertos and others with virtually all of the world's major orchestras and has given recitals throughout the world, with particular emphasis on the United States, Europe and Japan. Performing, he says, is "like a constant X-ray machine. You try to X-ray the work and see how and where it is going. Sometimes it's like engaging in a conversation, sometimes it's like telling a story. You can get very passive and let the music carry you, but if you do that you find yourself repeating what you have done before. I try to rediscover the music each time -- to play it as though for the first time, except that I also have to play it with complete familiarity and technical security.

"Sometimes, I find myself remembering the last time I played a piece of music, thinking, 'I didn't like the way this passage sounded the last time -- how should I change it?' But that is mostly for rehearsels. There are certain things that you can put on automatic while you listen to the music and concentrate on what it is all about, but you can never hear completely what is happening.

"Sometimes I feel bad when I'm playing -- everything I do seems to be a terrible effort, and I think it is sounding terrible. Then later, I play the tape of it and it sounds fine. The difference between what you think is happening and what is actually happening can be enormous. I'm trying hard to reduce that difference to a minimum."

One of the few musical mountains he has not yet climbed to his complete satisfaction is the Bach sonatas and partitas for unaccompanied violin. "That's probably the summit," he says. "I recorded them three years ago and played back the tape and didn't like it immediately. I think that's a sign of growth."

The rondo finale of Beethoven's concerto is circling around to its conclusion, and this man whose feet can never dance is dancing with his fingers, dancing in the music, engaging the whole orchestra in an enormous, superhumanly joyful pas de deux while sitting in a chair .

In places where he has to climb stairs before reaching the stages, Perlman says, "I think I should make them pay me for two performances -- one performance to get there and one on the violin. Sometimes I feel like I should have a cheering section to get me up the stairs: 'Come on, Perlman, you can do it . . just one more step now. . . There, you got it.'" His voice shifts to something between a cheerleader and a sports announcer.

"In some concert halls," he says, "I'm the only one who is being discriminated against: They are accessible to the audience, but not to me. Of course, I am a very small minority, but disabled people are not. There are 35 million of us in this country, and if we were better organized we could be a very powerful voting bloc.

"There are so many organizations and so many concerns: There is the movement for independent living, and the 'employ the handicapped' campaigns. There are organizations for the blind or for the deaf and for other disabilities, and we should get together in one umbrella organization. My dream is that someone like Norman Lear would start, a weekly television show with a central character who is handicapped. There was 'Ironside,' of course, but that was different. Did you notice that wherever he wanted to go, there would always be a convenient ramp? I noticed. I kept wondering if they would ever show him trying to get the wheelchair up a step and the wheelchair tipping over and Ironside spilling out."

"When you are in a wheelchair," he says, "people don't talk to you. Perhaps they think it's contagious, or perhaps they think that crippled legs mean a crippled mind, but whatever the reason, they treat you like a thing. I will be traveling, with someone pushing my wheelchair, and when we come to the passport station the officer will ask 'Where is his passport?' I always make sure that I have my passport with me, and I look up at him say, 'I have my passport.' I make him talk to me."

As the final echoes of the final chord die away the audience sits for a moment in complete stillness .

Itzhak Perlman reaches for the crutches that have been lying beside his chair and begins to get up slowly, supporting himself on the crutches, to bow (not very low). Then he begins to move slowly toward the podium to shake hands with the conductor, who is already rushing toward him .

And for a few minutes, the applause is so loud that you can't hear anything else; you can hardly think of anything else .

Like the long walk back to the wings .