When tasked to review this book, it immediately dawned on me how there is very little tutorial information about rhythmic concepts out there. Plenty of educational material deals with harmony and melody, but nothing I’ve seen presents the more challenging concepts of advanced rhythms quite like this book.
This material is geared towards intermediate and advanced-level players, and a basic understanding of rhythm and meter is required to properly digest the content. Rivera starts by defining metric modulation and polyrhythms, and proceeds to lead the reader through many exercises that both enlighten and prepare for what follows. Many of these examples involve foot-tapping and hand-slapping that I found quite useful, so the book is not just for guitarists; any instrumentalist, jazz or otherwise, can gain from Rivera’s thoughtful presentation. The examples that do include playing have tab notation for guitarists, along with standard notation. The audio demos that may be downloaded are invaluable in ensuring that the student has the proper understanding of the material.
All of the material is well-organized, concise, and clearly stated. The exercises are straightforward and are used to break down the somewhat larger and more complex concepts into smaller, more manageable ones. As an example, the explanation of the terms ‘fraction’ versus ‘ratio’ in Chapter 2 when defining the duration of polyrhythmic divisions. Another example of this is the method Rivera uses in Chapter 3 to define the construction of a polyrhythm inside a polyrhythm, addressing the quarter-note triplets. There is even an alternate explanation of the duration of these notes in an appendix at the back of the book, a thoughtful touch.
Once the basics are mastered, we are guided through various ways of analyzing, creating, and notating polyrhythms, polyrhythms within polyrhythms, and polymeters, using rhythmic ratios based on common denominators like quarter notes, eighth notes, triplets, and sixteenth notes.
Rivera’s explanation of implicit polymeters versus explicit polymeters is very useful and, again, clearly presented. He covers the fact that accents must be repeated for them to work as a meter, and explains that superimposing one meter over another is an alternate way to create an implicit polymeter. The exercises in this chapter are particularly beneficial. Sample song charts that employ these implicit polymeters are also included. Of course, explicit polymeters are easiest to spot as both meters are actually notated separately on a chart, and that’s covered also.
The final chapter ties everything together nicely with examples of how to employ what you’ve learned while comping, songwriting and improvising. The use of ‘harmonic anticipations’ and other rhythmic variations (whether improvising or comping) is defined and charted out for use as examples. The reader is guided through the process by the author here, unlike some books that tend to leave you with a feeling of being thrown in the deep end of the pool.
I often wished that the exercises were somehow set apart graphically on the page (like in a box, or shaded) so that I could refer back to them more quickly, but that is a minor gripe. There really is not much to dislike if you’re serious about tackling the subject matter.
Many musicians are at the point where they are often guessing when it comes to rhythms and meters that are not ones usually encountered. This book can help take that guesswork away and leave the student with a strong foundation to better understand and employ less conventional rhythms and meters. The Rivera-coined acronym IMTR (Isolate, Master, Transition, Repeat) is one all instructors should use when students need to tackle a specific issue. It’s apparent that Rivera spent some considerable time pulling this all together.
Mr. Rivera’s words of encouragement at the conclusion of the text are welcome, and can give any student some perspective on their progress. Alex Machacek is right on target when he states in the foreword, “I wish I’d had this book twenty years ago.” Highly recommended.