Harmony Theory

an easy guide to understanding keys for guitar players of all levels.

Calculus has been used in solving many scientific and engineering problems. For optimization problems, however, the differential calculus technique sometimes has a drawback when the objective function is step-wise, discontinuous, or multi-modal, or when decision variables are discrete rather than continuous. Thus, researchers have recently turned their interests into metaheuristic algorithms that have been inspired by natural phenomena such as evolution, animal behavior, or metallic annealing.

These are three classic texts on music theory and composition, dealing mostly with the "common practice" era of classical music (up to 19th century). A good knowledge of basic music theory is required. Highly recommended. –anonx