First of all, the title is a bit of a misnomer. Yes, there are transcriptions of Blues in all twelve keys. The transcriptions are 3 to 5 pages each. But what the beginning to intermediate bassist will find most usefull are the 33 pages, at the beginning of the book, demonstrating the various devices that Jazz Bassists use to construct effective bass lines. The Advanced player will welcome the books interesting exercises to use for keeping the chops up. Steven Moody, the author, guides the reader through exercises including Chromatic Approaches, Dominant 7th Chords, Harmonic anticipation, Voice leading tones, and Tri-Tone Substitution. Mr. Moody's book gives clearly written directions of the various techniques,followed by bass clef progressions that detail the examples. All the examples are interesting and go beyond the usual straight 4 beats to the bar that unfortunately fill up many of the books that I've purchased. I can see that this book will end up as dog-eared and ragged as my copy of Simandl, from repeated use.