What makes this book fun is Barry Green's insistence that a musician's choice of primary instrument ultimately reflects his or her personality, and the different virtues necessary for musical mastery can be glimpsed in conversations with different musicians.
It was instructive to hear how masters of different instruments cultivate attributes like joy, discipline, passion, and communication.
On the other hand, the chapter on "tolerance" reads like politically correct treacle (short version: when you play with an ensemble, do not insist on always getting your own way). PC also rears its comical head whenever Green's interview subjects credit God for inspiration, as at least two of them do. In those cases, Green quotes them, but switches abruptly to mention of a less-controversial "higher power" or "Spirit of Music" when summarizing their remarks. Personally, I was not the least bit offended to learn that classical guitar virtuoso Christopher Parkening seems well-versed in Christian scriptures and the practice of intercessory prayer.
Green sometimes succumbs to name dropping, which is admittedly a hard temptation to avoid in a book of this kind. After awhile, I was numb to the fact that he talked with luminaries as diverse as Frederica ("Flicka") von Stade (legendary mezzo-soprano) and jazz trumpeter Clark Terry. Green is "connnected" -- we get that. How nice for him.
Don't let Green's recurring (and sometimes annoying) patois about the "inner game" fool you. There are no "secrets" in this book. Musical mastery has to do with aptitude, it seems, but also and importantly with attitude, discipline, and personal integrity. Caveats aside, however, Green and his subjects say some good things, and the book is worth reading as a reminder to stay the musical course if you feel called to that.