The Inner Game of Music - a Recommendation

I'm recommending The Inner Game of Music by Barry Green.  I use a lot of the ideas in his book to help students cope with nerves and improve their concentration.  The book is fairly involved and therefore I would hesitate recommending it to anyone younger than 16. However, I often use the techniques and methods described in the book when working with young students.  As someone who has suffered from some performance anxiety I know how important it is to develop the right state of mind when playing or singing.  The sense of freedom that comes from a relaxed yet concentrated mind and body is quite liberating. It is often a students desire to succeed which leads to anxiety and consequently to them making mistakes.  Take that anxiety away, help them develop a new level of concentration and the results are immediate.