The Big Book of Pentatonics & Fourths (The Big Book of Pentatonics & Fourths is a series of four and six note groups that are developed into chromatic and diatonic lines. The concept of note groups was presented to me by the great pianist Hal Galper at the Jamey Aebersold clinic in 1980. I was young at the time but was hip to pentatonics so his ideas stayed with me and I’ve expanded on them in my own fashion.)