Gr 4-6 In the tradition of Jill Krementz (A Very Young Skater Knopf, 1979, etc.), Hewett photographs a child during a critical time in his life. Unlike Krementz' books, however, the prose is graceless and the photography, mundane. This does not necessarily mean that the book won't be popular. The subject, a charming eight-year-old boy whose day is packed with auditions for commercials and TV spots, should find a sympathetic readership among kids in elementary school who watch televisionespecially since he is auditioning for the part of Keith in The Mouse and the Motorcycle . The book is chock full of details about the dull routines and the excitement of getting a part. Readers will learn about children's acting classes and young theater groups, auditions, unions, composites, ``call-backs,'' sound stages, etc. There is an interesting explanation of the technique of shooting a commercial and integrating interior and exterior shots. Because there is no index, it may be awkward for use in research projects, but it should be enjoyable for a nonfiction book report. Sally T. Margolis, The Newport Schools, Kensington, Md.