Maurice Sendak is deeply bored by three fourths of his fan mail, school assignments sent to a man who hated school. The class has read ''Where the Wild Things Are;'' the teacher has drafted a form letter; an envelope packed with robotic notes turns up at his Connecticut farmhouse. ''Dear Mr. Sendak, I like when Max stands up in the boat. Yours truly....'' He rejoices in those kids who want -- who maybe need -- to send their weird, sincere appreciations and share fabulous bits of make-believe that freak him out. And he's got a thing for expressions of vigorous revulsion. ''Dear Mr. Sendak, I hate your new book and I hope you die. Cordially....'' As Sendak sees it, these correspondents often grow to realize that their hostility is a deep attraction. ''I've had any number of kids say, 'Your book scared the s--- out of me, but I couldn't put it down, and now I adore it.''' In any event, he gets less mail than he used to. He supposes people think he's dead.
He is a lively 75, with the look of an elfin professor, and sometimes, casting his quick eyes up at a book signing, he finds three generations of readers before him. ''I like that,'' he says. ''Their eyes are all glittering, and they all have very intense personal memories of me, so when they say, 'How do you write a children's book?' and I say, 'I don't know,' they're very annoyed.''
Sendak knows perfectly well how to write a children's book. He has written 17, illustrating those and nearly 100 others. He in fact knows how to write a children's book perfectly. ''The Picasso of children's books,'' Time once said. ''The Art of Maurice Sendak: 1980 to Present,'' a new retrospective by the playwright Tony Kushner, Sendak's friend and collaborator, opens with a line from one of countless prize citations: ''Maurice Sendak is the modern picture-book's portal figure.'' In 1963, The New York Times deemed him ''one of the most powerful men in the United States.'' That was six months before he published ''Where the Wild Things Are,'' about an unruly boy in a wolf costume who, sent to his room without supper, slips off to an island where he makes himself a master of giant beasts. The wildness of ''Wild Things'' -- its passionate plunge to the anger and fear and vulnerability of a child's inner life -- served to remake a genre. Like Sendak's subsequent classics, including 1970's ''In the Night Kitchen'' and 1981's ''Outside Over There,'' it can be read as a book for kids or as an adult work of art that takes childhood as its subject matter.
Sendak's oldest theme, he has said, ''is the tenaciousness of children to survive.'' The latest example of it comes in ''Brundibar,'' an antisentimental concentration-camp fairy tale.
What Sendak does not know is why he can't hold himself back from writing them, why his fantasies take their form. ''I accept that I'm a writer of books for children,'' he says, ''but it isn't anything I planned. Maybe it's what I have to do.''
Sendak is sitting in a hard chair in a small red barn down the road from his house. The most conspicuous decorations are ''Wild Things'' dolls and some antique buttons from a vast collection of Mickey Mouse memorabilia. ''The early Mickey, with the jauntiness and the outrageous behavior. He didn't become a s---head till much later.'' The barn is a place for working on bigger projects -- especially the operas Sendak's been designing for the past 25 years. ''Brundibar'' started as one of these.
Composed by Hans Krása, this allegory exhorting resistance to the Nazis premiered at a Jewish boys' orphanage in Prague in 1942. Its heroes, a brother and sister, try to sing for money to buy milk for their ailing mother but are bullied by Brundibar, a teenage busker. To drive him off, they need the help of a few animals and a chorus of schoolkids. And so they make the money and buy the milk and all is well. ''Brundibar'''s original cast and crew were shipped to the concentration camp at Terezin, Czechoslovakia, where they put on the show 55 times. Krása, like most of his performers, was murdered at Auschwitz. Sendak's book editor, Michael di Capua, says, ''What's been going on for Maurice since he first heard the opera, which was about six years ago now, was that the lightness of the opera itself intermingled with the dark backstory, and this was a key for him to express so much that he needed to get off his chest.''
While Hitler was slaughtering Europe's Jews, Sendak was growing up in Brooklyn, the youngest child of two Polish immigrants. Life felt chancy from early childhood. Bouts of the measles and scarlet fever were followed by the Lindbergh kidnapping and the Hindenburg explosion. (Which is not to mention the menace the everyday world holds for an uncommonly sensitive kid; the ''Wild Things'' monsters were equally inspired by King Kong and young Maurice's aunts and uncles, the faces looming from above saying ''We could eat you up.'') But the war and the Holocaust, Sendak says, ''seemed to intrude into every aspect of childhood so that I felt doomed.'' First he felt guilty for enjoying ''Pinocchio'' while a war raged in Europe; then he felt guilty for being alive.
He's been edging toward the topic of the Holocaust for decades, and he wanted ''Brundibar'' to be a powerful summation. Kushner, who wrote a new libretto for the opera and reworked it for the book, got an education in Sendak's perfectionism in the process. ''The first take that Maurice made on 'Brundibar' was really quite lovely,'' he says. ''Then he got cranky and angry about it, and since he sometimes gets cranky and angry about things that he shouldn't be cranky and angry about, I was, at first, dismissive of his complaining. And then I saw him throw out everything he'd done and really go into a very painful period of doubt about it and then come out of that with this renewed ferocity.'' That ferocity -- the pure attack -- is what makes him go, the perfection of lines and purging of feelings. Sendak's editor thinks history will view the book as the masterpiece of his maturity. The author himself says he really doesn't care.
''Getting the book printed and out into the world is not my motivation. It's nice. And people like it, they praise you, niiiice. But that's all. I mean, it was: staying up all night. Working on this book. Listening to music till I was gonna puke. I couldn't stand music. Three in the morning, putting on TV, watching some stupid porn thing while I was doing this heartbreaking story. Fuuun. Fun to work with all these elements. And that's the whole thing.''