Perhaps the first English translation of Kepler's 1619 explanation of musical relations and their application to the motion of the planets. It had little influence because Kepler favored a realist Platonic view of geometry that differed from the algebra and symbolism that had become popular over the previous century, and the discovery of inertia and Newton's work soon contradicted the Aristotelian theory of motion Kepler based his work on. His ideas however bear some resemblance to the concept of dynamic resonance used by astronomers today. The translation is clear and precise, well supported by notes, and accompanied by the original illustrations. Annotation c. by Book News, Inc., Portland, Or.