This unconventional method book, by Medeski Martin & Wood drummer Billy Martin, is a serious four-way coordination workout based on a series of four-, six-, and eight-beat Afro-clave patterns and a few odd-note rhythms. Each clave is presented in the author's unique notational system, which uses X/s for played strokes and periods for rests. The book gets progressively more difficult as various bass drum figures and left-foot/left-hand accompanying patterns are added to the mix. On the included CD, billy demonstrates many of the examples to help you get an understanding for how hard these things can groove. --Michael Dawson, Modern Drummer Magazine