The major positive traits of this tiny book are that it gathers in one place the information that up to now had been scattered in papers, open-source code descriptions, and specialized Internet forums (mostly academic ones), and that it provides an example of MATLAB code on the book’s Web site (http://www.audiocontentanalysis.org/) that is easy to understand and use.
After an introductory chapter, the book begins with a chapter (2) devoted to elementary concepts in digital audio signals and their basic transforms (Fourier, constant Q, and auditory filter banks). Chapter 3 introduces the so-called instantaneous feature, in other words, a numeric qualifier for a short segment of the signal being analyzed. The emphasis is on statistical qualifiers, such as moments, and spectral shape qualifiers. The descriptions are concise and ready to use in applications that would need these features. Chapter 4 gives a short description of some intensity features, such as signal envelopes. Tonal analysis, which includes pitch processing, is given more thorough treatment in the next chapter. Chapter 6 presents details in the area of temporal analysis, such as tempo, beats, and onset detection. Chapter 7 concludes the discussions on features and their extraction with a discussion of algorithms for time alignment, including dynamic time warping.
The last three chapters are devoted to basic applications, some of which are well known to smartphone users, such as musical genre recognition and music similarity, described in chapter 8. Chapter 9 gives a glimpse into audio fingerprinting. The last chapter introduces music performance analysis.
There are four appendices, a short description of convolution properties, a lengthy description of Fourier transforms, a two-page courtesy mention of principal component analysis, and a quite useful summary of some of the major (and best so far) open-source software platforms that are either devoted to or usable for audio content analysis.
Overall, this is a very practical book. It’s a good source of concise information on many topics in audio analysis, and I recommend it for practitioners of digital audio.