It has been a real joy to read and I can talk your ear off about it.
The first chapter goes into the creation of music. The cultural landscape that various musical forms (classical, symphony, jazz, blues, hip-hop) were born from. The ideas are intriguing and make some music forms make a whole lot more sense.
I found the idea that Jazz and Blues derived their unique musical patterns (licks, riffs) from the need to provide extended playtime to music that was ultimately played for dancing and having a good time. The singer could not sing all night so the musicians needed to improvise so as to extend the dancing and enjoyment of a piece for the listening audience. The more the dancers were into the song, the longer it went on, using these repeating riffs. Riffs lived or died by their ability to hold the crowds attention.
He also explains how certain types of music don't work in various venues since the venue where music was originally written for is the best place to hear that music. It explains to me why bands I have seen play in opera houses sound terrible. In the right setting, I am sure that those bands would sound much better. They certainly sounds better as an MP3.
An interesting discussion revolved around how recorded music changed the way artists play. I found it very interesting to know that due to the limitations of recording live music, recorded music caused the style of play (say, muffled drums, or the use of vibrato for stringed instruments) to change for both recorded and live music.
The best example of recording impacted technical musicianship was around vibrato used by Opera singers and by violinists. Before recorded music, vibrato was considered poor style and a cheap trick. With recordings though, the pure note sounded harsh and without life. The impact was that for recordings, stringed instruments started to add vibrato. Vibrato is basically a wavering of the note just above and below it's true pitch. Our ears/brains then translate that into true pitch. On a recording this causes the note to comes out truer and with more life.
This same trick is used by Opera singers since the introduction of recorded music. Apparently, Opera used to sound more similar to the way Pop is sung today (as in, you can understand each word). The introduction of the wavering to the voice was again to added to make the performance sound better on recorded medium. So today we have music that is only performed in a manner that best suits recordings failings.
That is only a minor scratching of the surface of this book. If you are into music then this book will open your eyes to the many ways that music is created and how it works. I've found it extremely enlightening but it is not always an easy read. There is a lot to take in here but the reward is a stronger understanding of recorded and live music. What makes them unique, their limitations, their impact, and how we have evolved music to fit our time.