I had the opposite experience. Sack's book is focused on abnormality,
which I did not find interesting. I'm not really much interested in a
non-musical man who began to compose music after being struck by
lightening. Levitin's book, on the other hand, I found very interesting
as it explores the effects and interactions of a normal brain with a
seemingly random set of rhythmic sounds.
I'm about half through "Guitar Zero." I'd say that it is more about
learning with the guitar as the medium being learned than it is about
playing the guitar.
TW