The initial problem with this book is that it's dated -- it tells the history of CCM up to about 1980. Putting this limitation aside, it's an interesting account of (part of) that history, albeit strongly US-centric. The bigger problem is it's focus: when Baker talks about the struggle for acceptance that CCM faced in it's early years, he means acceptance by the church. Not acceptance by the entertainment business or commercial radio or the music press or other musicians or rock fans, etc. The goal is acceptance by the church. Getting contemporary music into the church is the goal. Big deal! There is no attempt to discuss CCM as a genre within the music biz. This is a major failing IMO. It's still a useful entry point read, just don't expect any major insights.
Imagine a world where the only Christian music available was in the form of hymns, and the Salvation Army brass bands. Thank God for Christian musicians!