One of the earliest and most important books to subject jazz to serious critical analysis was Winthrop Sargeant's Jazz: Hot and Hybrid (third edition published by Da Capo Press). One particular aspect of this book forms the foundation of this Piano Today article, which might serve as the basis for an easy approach to the teaching of early-level jazz improvisation.

Tetrachord

What is a tetrachord? It's a succession of four diatonic scale tones, encompassing the range of a perfect fourth. It has the following interval arrangement: major second, major second, minor second.

A major scale consists of two tetrachords separated by the interval of a whole step:

Blue Notes

Blue notes are deliberate ...