Common Tones

               I was practicing the changes of "All The Things You Are" (out of The New Real Book) the other day and reflecting on what a well written song it is.  For me, the best quality within the song is the structure of the chord changes and the common tones within the voicings.  There are so many beautiful ii - V - I progressions within this tune that weave through a variety of key centers.  Each time this happens a few pitches change while much of the voicing remains intact.  These beautiful harmonic changes occurring across minimal motion cause the ear to be intrigued and captivated. 

                Even outside of the ii - V - I progressions there are moments of common tone chord metamorphosis.  My favorite example of this is the change for Abmaj7 to Am7b5 toward the end of the A section.  These are two very different chord qualities, and they produce very different sounds.  At first glance, a piano player may think, "Wow, this is going to be a drastic change!  How should I voice it?"  After further analysis, however, you realize that the upper pitches can remain motionless as the bass moves up chromatically.  This slight chromatic motion in the base line transforms on chord into another and shifts you into a totally different key center.  In an age of predictable pop songs it feels good to listen to a classic such as this and have your ear challenged for a change.