On the Sensations of Tone as a Physiological Basis for the Theory of Music (German Die Lehre von den Tonempfindungen als physiologische Grundlage für die Theorie der Musik), commonly referred to as Sensations of Tone, is a foundational work on music acoustics and the perception of sound by Hermann von Helmholtz. Helmholtz declared that he started working on his book in 1854, which concluded in 1862. The book's introduction, Dover edition from 1954, by the German physicist Henry Margenau, with a list of selected publications by Helmholtz, is available here.