ABSTRACT
This chapter introduces the basics of mainstream jazz harmony. Perhaps most important is the omnipresence of triad extensions—sevenths, ninths, and thirteenths. Jazz treats these triad extensions as chord members in good standing that do not necessarily require resolution. Few things are as daunting as a comprehensive table of jazz harmonies. One reason for more elaborate symbols is to promote agreement when there are multiple chord instruments in a rhythm section about which extensions and which alterations to use. Chord substitution results when jazz players seek to vary commonplace harmonic patterns. Because the search for new interpretations is ongoing, chord substitution has grown into the 800-pound gorilla of jazz harmonization. Jazz makes extensive use of auxiliary chords—passing chords and neighbor chords to fill the intervals between principal harmonies, appoggiatura chords to accentuate those harmonies, and so on. Jazz harmonization is endlessly fascinating, and the processes can seem fascinatingly endless.
