The book is essentially a collection of smaller essays that range from the opening tale of a man who is struck by lightning and suddenly seized with the relentless desire to play piano to people who suffer from musical hallucinations. In between are discussions of Williams Syndrome, music therapy, brain scans of professional musicians and other sometimes troubling/sometimes rewarding stories.
One of the most troubling of these stories involves an English musicologist named Clive Wearing. After contracting a severe brain infection, his memory was limited to just a few seconds (if that's not one of the most terrifying things you've ever read in a non-fiction book, what is?). In spite of his condition, Wearing can still play piano -- implying that somehow the memory of the music is embedded somewhere else in the brain. It's a weird study of how we can live in the present and still hold on to some intrinsic understanding of our own history, even if we don't realize it.
Sacks describes several of these types of tales in such a way that even the most brainless of us can understand. It's not a book about the science of the brain's reaction to music so much as it is about the people. This connection is what makes it interesting for us non-Ph.D.-qualified types, and Sacks shows that he can explain complex ideas in an entertaining fashion.
It's hard not to walk away from Musicophilia with a sense of dread and envy. The book features a cross-section of the horrifying balanced with the magical. Synesthesia sounds like a lot of fun, but Williams syndrome sounds like being trapped in a box. Being hard-wired to write and create music seems like an awesome turn of events; being struck by lightning, however, doesn't sound like fun. It's this balance that adds the humanity needed for these stories to be interesting, and Sacks captures it time and again through each of these essays.
The stories here are worth reading if you're a fan of music, if you play music, or if you just love wacky, odd science.