Very good information, rather scattered in its organization.
Music is an incredibly broad topic, and this book attempts to deal with every hidden corner. It is ecumenical, addressing every genre with equal enthusiasm.
It does a good job of addressing the historical evolution of instruments. It has wonderful photographs of the very earliest whistles constructed by cavemen, lyres constructed by the Greeks, pianos and stringed instruments throughout the ages.
It does not do quite such a good job of describing how they work. I would like to know why a trumpet has valves. Why is it that bass instruments are bigger than trouble instruments? How does sound resonate in a hollow tube?
The diagrams of the history of music are a little bit too cute. A barely discernible trend line snakes back and forth across the page leading from one development to the next. The result is graphically interesting but it does not leave a great deal of room for text and it is hard to follow. I would've rather had a more prosaic list in chronological order of things such as, for instance, the way composers elaborated on each other's work throughout the Baroque Period.
The historical development is useful as an overview. It is nice to know that Palestrina was early Baroque; the Baroque period went from about 1600 to 1750, followed by the Classical through 1820 and then the Romance through the early 20th century. In the realm of classical music, it puts the weight where it ought to be, treating most 20th century orchestral music as rather a footnote to the great compositions of the preceding centuries.
The book is studiously agnostic with regard to the quality of music. It does not hesitate to name George Gershwin as a musical genius, but it does the same for pop stars such as David Bowie. I regret that I'm just an old fogey who likes to pretend that there was quality in earlier music that is absent today.
I bought this to teach my five-year-old about music. I'm sure we will use it, but it is not as useful as I would've hoped. Four stars.