As a bassist and longtime Jaco fan, I wanted to get deeper into his playing, so I got this book. I must say it is obviously very helpful to see his lines written out. My ear is not that great, so fast passages are very hard to pick out by ear. But, even his slower lines have many nuances that escape the ear. Now, the CD offers slowed down versions of some of the lines, which is great. But why not ALL of them? I mean, lines as complex as Donna Lee or Teen Town do not appear as slower versions on the CD, and that is a major bummer. In fact, the whole point of the CD in my opinion would be to have these slower versions to aid your practice. For the normal speed versions, I could just buy the albums, I really don't need them here. But, that is my only gripe. If you play the bass, and you would like an overview of Jaco's major contributions to the electric bass, this book will do just fine. There are other books that actually transcribe whole songs, but this one includes a couple of choruses of each and the bass solo if there is one. I think this is good enough, as with that much material one gets a clear idea of Jaco's concept for the song. I don't really need a transcription of his 12th chorus of the same tune, with 2 or 3 I get a clear enough idea of his style and technique. Enough so that I could eventually incorporate his ideas into my own playing. If you want complete transcriptions, look elsewhere, as this book's only complete song is "Portrait of Tracy." But to learn Jaco's style and techniques, as the title clearly states, this one is great.