This book (with accompanying CD) is e great resource for training in improve technique fundamentals. The exercises will help you develop lip and finger flexibility as well as a good sense of accent and flow. John's written introduction to the history of Jazz Trumpet is exceptionally well written and whether you agree with all of his views or not he writes nearly as well as he plays! I frequently use this book as an exercise book to travel with when I don't want to carry a stack of practice material. Players young and old who want to develop their Jazz chops will benefit from its use.