This book provides a wide description of the physics of sound, emphasizing fundamental issues and the connections with other branches of physics. From its production in musical instruments to its transmission through air, from its perception by humans (including aesthetic issues such as musical scales) to its digitization and manipulation, from its artificial synthesis to its reproduction, the study of sound represents a unique opportunity to link ideas, concepts and formal treatments which appear throughout all of physics, with the added benefit of an intuitively understandable phenomenon we are all familiar with. The unifying "fil rouge", the common thread interweaving the chapters of the book, is the unity of physics: while the text can definitely be used to get a solid understanding of the basis of acoustics and related topics, an equally important goal is that of allowing the reader to identify connections and similarities between phenomena, which help forming a deeper understanding of the underlying physics, and hopefully help conveying its beauty which, just as for music, transcends content and touches form.
Starting from ideal oscillators and spectra, moving through mechanical ones of increasing dimensionality and touching non-linear effects, the discussion traverses standard sound propagation to reach the human ear and psychoacoustics, addressing mechanical, electrical and electronic instruments, as well as more recent topics of digital music; from Pythagoras' monochord to MP3 files, sound allows to traverse an evolution of understanding which literally spans millennia, arguably more than any other investigation of Nature. Some appendices are intended as very concise refreshers of some general physics topics, to help remind the reader about key concepts, if needed.
The book is aimed at advanced undergraduate science students with a solid background in general physics who are interested in learning the foundations of the physics of sound or to glimpse the unity of physics through acoustic phenomena, as well as to more advanced curious scientists from other fields who are looking for possible surprises in finding out things they know in a different context. The online edition includes illustrative sound samples.
