My interest and subsequent study of twelve-tone music and serial compositional methods led me to writing a series of improvisation exercises which would eventually become this book. In this book  I describe one small corner of twelve-tone/ musical set-theory in which groups of three pitches (trichords) are used as building blocks for twelve-tone rows. Each row only uses one set of three pitches (trichord) to generate the entire content of a twelve-tone row. The twelve-tone rows generated from these 12 trichords each have a specific sonic quality and have structural relationships to each other as well as to the symmetric scales commonly used in jazz. These relationships provide us with a system of "harmony" which can be used when improvising.
-John O'Gallagher