Steve Vai's Guitar Workout is a excellent collection of wisdom from one of the greatest guitarists of our time. Although I thought I knew quite a bit about practice methods, I instantly discovered new ideas and things I could do with the instrument. Steve's approach is brilliant, because he is not focusing solely on the technical side of things - yet mastering that is also essential - but more importantly, he puts emphasis in addition on musicality and expression. I recommend Steve Vai's Guitar Workout to anyone interested in developing his/her abilities. Concise and informative.