So What chord

In jazz and jazz harmony, a So What chord is a particular rootless 5-note chord voicing employed by Bill Evans in the "'amen' response figure" [John Robert Brown (2004). "Mel Bay's Concise History of Jazz", p.146. ISBN 0786649836.] to the head of the tune "So What".

The term is used extensively in Mark Levine's landmark work "The Jazz Piano Book", wherein he describes a range of uses for which the voicing might be employed. Frank Mantooth dedicated two chapters to the chord under the name "Miracle voicing" in his work "Voicings for Jazz Keyboard".

From the top note downwards, it consists of a major third followed by three perfect fourths, and is identical to the standard tuning of a guitar's bottom five strings (minus the top E-string). It is essentially a minor eleventh chord (-11, m11), arranged as it would be played on a guitar (root, 4th, b7th, b3rd, 5th). It may also be used as a Major7#11 chord if a bass note is used that is a tritone away from the top note, or as a simple Major7 chord if the bass note is a major seventh away from the top note.

It may also be thought of as a five-note quartal chord (built from fourths) with the top note lowered by a semitone. More modern sounding than "tertial chords" (built from thirds), it useful in comping since the structure of quartal harmony is usually vague many roots may be applied to the So What chord and it may sound well in various contexts including, "a major scale context; a Mixolydian mode context; or a minor context" [Martan Mann (1997). "Improvising Blues Piano", p.81. ISBN 0825616247.] .

Other jazz recordings that make extensive use of the chord include McCoy Tyner's "Peresina" and Gary Burton's "Gentle Wind and Falling Tear."

Bibliography

*Levine, Mark "The Jazz Piano Book" 1989 Sher Music Co., Petaluma, CA ISBN 0-9614701-5-1.
*Mantooth, Frank "Voicings for Jazz Keyboard" 1986 Hal Leonard Publishing Corp., Milwaukee, WI ISBN 0-7935-3485-2.

Sources