This book contains 110 systematically organized ii-V-I phrases. All phrases in this book are “long” ii-V-I, meaning that they span across three measures each. Jazz musician and scholar Gunther Schuller estimated that ii-V-Is roughly represent 70% of all harmonic progressions in tonal jazz. Accordingly, it is essential to be prepared to navigate this crucial progression in every situation (i.e. all keys and tempos).