Par CHRISTIANSEN COREY. John Coltrane's recording 'Giant Steps' introduced a system of chord progressions and chord substitutions that has challenged even the best jazz musicians. The tri-tonic systems (sometimes referred to as 'Coltrane Changes') found in the tunes Giant Steps and Countdown is taught in a digestible way thoughout this method. Etudes show how to reharmonize standard ii-V-I changes…