This is an excellent book and CD. In 5 highly listenable-to and accessible tracks, Calva covers the key electric blues phrases and styles, at a range of tempos and rhythms, from slow BB-King-esque bendy blues to shuffles to driving, funky blues. It references all the greats, including BB (not texan, but his licks are in here!), Albert King, Albert Collins, Freddie King, Johnny Winter and SRV. For the player who has got a few minor pentatonic licks under their belt and wants to take this to the next level, its an unparalleled introduction, and serves as a compendium of key licks and phrases.
There is plenty to challenge, from some quick-fire licks to getting the slower, bend-based phrasing right (an essential skill), but none of it is out of reach of the 'improving' player. And unlike many books, it encourages the student to focus on the construction of the rhythm tracks too (which are also tabbed in full) in addition to the lead parts - an essential part of becoming a good player, and criminally neglected by most books!
The author also adds plenty of accompanying explanation, tips and comprehensive parting thoughts, without ever becoming tedious, and includes his 'essential albums' discography, which helped me out no end a few years back. I am now an experienced player and starting to teach too - of all the tuition books i have ever purchased, this is the one i have got the most mileage from, setting me on the right path as a blues player myself, and again for inspiration in teaching the blues to others (thanks, Robert, if you ever read this!).
Also check out Calva's other book- blues/rock guitar, also highly recommended, but only after you can nail the stuff in this book; the other one is rather more challenging throughout- lots of high tempo licks and longer, more complicated structures.