Introduces the spectral and inverse spectral theory of Jacobi operators and applications of these theories to the Toda and Kac-van Moerbeke hierarchy. The author investigates the advanced topics of locating the essential, absolutely continuous and discrete spectrum, subordinacy, oscillation theory, trace formulation, random operators, almost periodic operators, (quasi)-periodic operators, scattering theory, and spectral deformations. An appendix reviews the theory of Riemann surfaces as needed in this monograph. Annotation copyrighted by Book News, Inc., Portland, OR