A NEW BOOK by the award-winning children's author, Katherine Paterson, is always a welcome event, and this one will not fail her readers' expectations. Well-known both for novels of historical China and Japan and for those with a contemporary American setting, Katherine Paterson returns here to the local landscapes she brought so beautifully to life in Bridge to Terabithia and Jacob Have I Loved. Come Sing, Jimmy Jo moves back and forth between rural Appalachia and the fictional city of Tidewater, Virginia, local capital of traditional country music. It is also a book of unusual zest and perceptiveness, which will only enhance Paterson's reputation as a master storyteller.

Consider the opening paragraph: "Grandma stuffed a pinch of homegrown tobacco in her pipe, scratched a kitchen match on the side of the rocker, and puffed to make the light catch. 'Awright, James,' she said between puffs, her teeth clenched on the pipe stem, 'I wanna hear you really tear it up now.'"

The crackling vitality of the prose here catapults one right into the story, but this apparently artless paragraph also accomplishes more. It draws our attention at once to the book's central relationship, between 11-year- old James Johnson and his grandmother, and it also establishes the dominant theme: music. For James and his grandmother are Johnsons of the Johnson family of Wesco, West Virginia, who, like the legendary Carter family, live by and for little but "picking and singing." Grandma's voice is cracked now, but her sense of timing still "just made the very hairs on your head rejoice." James' mother, Olive, has "a voice that could blow the colored glass out of the back of a church." Uncle Earl is pretty near as loud as Olive, and Jerry Lee, James' daddy, is the best banjo-picker in three counties. Young James himself sings like "a angel."

THE REMARKABLE thing about Come Sing, Jimmy Jo is the way Katherine Paterson is able to bring music to life through her prose, always a difficult thing for a writer to do convincingly. This is not just a story about country music. The whole book sings. "The enchantment had poured out from his body through the air. . . This must be how it feels, he thought, this must be how it feels to have the gift." The little boy is his music. Telling Jerry Lee about his new teacher at the General Douglas MacArthur Elementary School in Tidewater, James says, "Grandma used to say 'Everything dances.' I ain't so sure. I ain't seen no music in that man."

But the book is more than a lyric celebration of country music. Great pressures are brought to bear on the Johnson family and little in their lives remains simple anymore, despite the comforting simplicity of the songs they sing. Success comes, in the form of a six-month contract to perform every week on the "telly vee' in Tidewater. The whole family, except Grandma, moves to the city. Olive becomes Keri Su, James is transformed into Jimmy Jo. Strange things are going on between Keri Su (James' momma) and Uncle Earl; there are fights about the kind of music the family should sing; James is hounded by a stranger in a black pickup; and, most disruptively of all, Jimmy Jo becomes a star, which opens up all kinds of fissures in the family structure. "Jimmy Jo" fights to hold on to that integral part of himself which is "James," the part which really belongs to his grandma, back home in West Virginia.

Like all Katherine Paterson's novels, Come Sing, Jimmy Jo is full of what she has called "strong themes," the harsher aspects of human life which she feels children, too, need to read about: loss, misunderstanding, fear, betrayal. At the same time it is as alive and hilarious as any book children are likely to read this year and in that, perhaps, lies the "stubborn seed of hope" she has promised always to plant for them.