Leonard Bernstein begins this companion volume to his popular Joy with an imaginary conversation with his favorite spirit, George Washington, in which he pronounces on the need to teach people to read music. That skill would extend the interest and usefulness of this book, for it is chockablock with musical notations. For the person seriously interested in music but not necessarily, indeed, not versed, Mr. Bernstein's exposition is a joy. Five TV transcripts take up such questions as ""How can it be that those Occidental oceans of different musical works come out of just one dozen notes?""; discuss jazz in serious music; the ageless Mozart (""He captured not only the feel and smell and spirit of his age but also the spirit of man""); rhythm, and romanticism in music. Four symphonic analyses form the heart of the book: Dvorak's Symphony No. 9 in E Minor (""A New World symphony from the Old World, full of Old World tradition""); Tchaikovsky's ""Pathetique""; Beethoven's Eroica (""In all the realm of the arts you will never find a simplicity to match Beethoven's""); Brahms No. 4 in E Minor, First Movement (""a microscopic look at symphonic method""). A University of Chicago lecture in 1952 takes up the nature and methods of creativity and communication. Masterful, vital popularization which charms as it edifies.