Advanced Rhythmic Concepts for Guitar is a step by step guide through the process of identifying, dissecting, constructing, practicing and applying: Metric Modulations, Polyrhythms, “Ratio” Polyrhythms, Polyrhythm Divisions/Polyrhythms within Polyrhythms, Intrinsic Polymeters, Extrinsic Polymeters, Polymetric Accompaniment, and Polymetric Improvisation.

As for the books relevance towards the jazz/fusion and avant-garde communities, I refer you to some of the many stellar reviews received by highly esteemed musicians, as well as authors of the aforementioned genres:

"Jan Rivera's book is clear, thorough, and methodical, and will be an asset to anyone wishing to improve in the area of rhythm. Having the fluency to freely play with polyrhythms and polymeters is a valuable skill for the modern improvisor, and careful study of this book will provide the student with the tools needed to achieve this."  - Ben Monder

"Guitarist Jan Rivera has produced a thorough, easy to understand guide to metric modulation that will be very useful to any serious musician. There are hundreds of examples in this book illustrating and breaking down rhythmic concepts in pragmatic ways that will make their applications possible. Highly recommended". -John Stowell

"Rhythm is such an important and under nourished aspect of playing and studying music.  Jan Rivera has come up with an informative, challenging and clear concept for understanding and using complex rhythms.  The book is called "Advanced Rhythmic Concepts For Guitar", but I really feel that this book will benefit any musician; no matter what instrument they play.  Just the Ratio Polyrhythms section is a great help in organizing one's thinking about that difficult subject. I highly recommend this book for anyone who is serious about improving their overall knowledge of how rhythms work and more importantly how to use them effectively." -Dean Brown 

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