2001, by Stuart Isacoff. "A fascinating and hugely original book that explains how a vexing technical puzzle was solved, making possible some of the most exquisite music ever written. From the days of the ancient Greeks, the creation of music was thought to be governed by divine and immutable mathematical certainties. But over time skeptics came to understand that those rules limited harmonic possibilities. InTemperament, we see the traditionalists and the innovators battling across the centuries, engaging great thinkers like Newton, Kepler, and Descartes as well as musicians, craftsmen, church leaders, and heads of state. At the heart of their dispute is the question of how the tones of a musical scale should be selected. The breakthrough came in the eighteenth century, when the modern keyboard was given perfect musical symmetry through a tuning of equal temperament, each pitch reliably equidistant from the ones that precede and follow it. This tuning allows a musical pattern begun on one note to be duplicated when starting on any other; it creates a musical universe in which the relationships between tones are reliably, uniformly consistent--a universe of greatly expanded possibility, one that allowed Liszt, Chopin, Brahms, Debussy, and all those who followed to compose the piano music we listen to today. Stuart Isacoff relates the story of the reinvention of the piano--a story that encompasses social history, religion, philosophy, and science as well as musicology--in a concise and sparkling narrative.Temperamentis a jewel of a book."
1997, by William Sethares. "Tuning, Timbre, Spectrum, Scale focuses on perceptions of consonance and dissonance, and how these are dependent on timbre. This also relates to musical scale: certain timbres sound more consonant in some scales than others. Sensory consonance and the ability to measure it have important implications for the design of audio devices and for musical theory and analysis. Applications include methods of adapting sounds for arbitrary scales, ways to specify scales for nonharmonic sounds, and techniques of sound manipulation based on maximizing (or minimizing) consonance. Special consideration is given here to a new method of adaptive tuning that can automatically adjust the tuning of a piece based its timbral character so as to minimize dissonance. Audio examples illustrating the ideas presented are provided on an accompanying CD. This unique analysis of sound and scale will be of interest to physicists and engineers working in acoustics, as well as to musicians and psychologists."
1972, by J. Murray Barbour. "The demands of tuning (attaining the perfect scale) and temperament (the compromises necessary for composing in every key) have challenged musicians from the earliest civilizations onward. This guide surveys these longstanding problems, devoting a chapter to each principal theory and offering a running account of the complete history of tuning and temperament. Organized chronologically, the book features a helpful glossary and numerous illustrative tables, and it requires minimal background in music theory. "