Hey Jazz Guy,
I’m mystified by “Giant Steps” and “Coltrane changes.” Can you explain how that harmony works? —Confused in Cambridge

Dear Confused, John Coltrane’s 1960 tune “Giant Steps” represents a landmark moment in jazz. The chord changes differ radically from other music of the time, and they have proved challenging ever since. We will break it down and examine this fascinating piece of music. The harmony derives from a three-tonic system. If we divide the octave into three equal parts, we get three notes, each four half-steps apart, for example B, Eb, and G. Then we build major triads on these notes [Ex. 1], and they will be our three tonics or key centers. The genius of the progression is that Trane then put the relative dominant chords in front of each major chord to make the resolution stronger. The first half of the progression, as seen in Ex. 2, illustrates this technique, starting with Bmaj7, then dominant (D7) to the next tonic (Gmaj7), followed by another dominant (Bb7) to the last tonic (Ebmaj7). Notice that a IIm-V is used to “recycle” the tonics and start the sequence again on Gmaj7. The second half of the progression in Ex. 3 just places IIm-Vs as preludes to each key change, beginning with Eb, then IIm-V to G, IIm-V to B, IIm-V to Eb, finally another IIm-V to get back to the top. Because the motion of the chords is so complex, the aim when soloing is to play very accurately over the shifting tonal centers. Over the first four chords [Ex. 4], the line is almost exclusively chord tones. This is important because when the harmony changes so rapidly, it must be clearly articulated by the soloist in order to sound “correct.” Practice each piece of this tune slowly and carefully, taking one small step for you, and one Giant Step for your jazz education!

Jake Hertzog is the jazz ambassador to the non-jazz world. Send your questions to guitplyr@musicplayer.com. Jake’s latest release is Evolution [Buckyball].