Guitar Zero: The Science of Becoming Musical at Any Age (2012) by Gary Marcus is an account of Marcus’s time learning guitar and his view of how learning music works. Marcus is a cognitive scientist so he is in a great position to describe how to learn music.
Marcus took a sabbatical to learn the guitar despite having less than average rhythm. His account of learning interspersed with the cognitive theory behind learning works really well. It’s an inspiration to anyone who has thought about learning a musical instrument as an adult.