A Technical Note on Monk’s Music
Monk’s unique sound has a lot to do with how he voiced his chords. As early as 1941, he was already experimenting with “open” voicings—i.e., sometimes playing just the root and seventh of a dominant or major seventh chord, eliminating the third and fifth. The impact on the ear is quite startling. A standard major seventh voicing with the root at the bottom—C–E–G–B—sounds consonant, but remove the E and G and suddenly you have a highly dissonant chord, because the two remaining notes are only a half-tone away from each other. Invert the chord and you have a minor second. Often he would eliminate the root altogether and just play the seventh or the ninth in the bass.1
Dizzy Gillespie gave Monk credit for introducing the half-diminished chord, a minor seventh chord with a diminished or “flat” fifth (e.g. C–Eb–Gb–Bb). Monk, however, called that example an Eb minor sixth rather than a C half-diminished chord.2 Whatever we call it, it became an essential element of Monk’s harmonic language, partly because of the dissonance created by the C–Gb. That flatted fifth or “tritone” was critical to what would become his harmonic signature: descending chromatic chord changes. Pop songs and much of jazz up to that point built standard chord progressions around a cycle of fifths (e.g., the standard ii-V-I cadence, popular from the baroque era to Monk’s day). Monk preferred to move chromatically, so in place of the V (dominant) chord he substituted a bii7. In the key of C, instead of G7, he would play Db7. The cadence became Dm7–Db7–Cmaj7. Three of the four voices moved in parallel, chromatically (e.g. the bass voice, D–Db–C, and the alto, A–Ab–G). This is called “tritone substitution,” because the new chord is a tritone distant from its predecessor. Monk did not “discover” tritone substitution, but his employment of descending chromatic chord progressions and the use of the dissonant tritone interval along with whole tone harmony became defining characteristics of Monk’s sound.
And yet, Monk sometimes pared down his chord progressions—most commonly on the A-section of his own “Rhythm-a-ning” and other songs based on Gershwin’s “I Got Rhythm.” Typically, the eight-bar A-section called for chord changes every two beats and the first four bars (usually repeated or replaced with substitute chords) follow a I-VI-ii-V pattern (e.g., Bbmaj7 Gm7 | Cm7 F7).3 But Monk reduced all of that to a riff on one chord: Bbmaj7 or Bb6. We hear evidence of this going back to his first recordings at Minton’s Playhouse, particularly on a tune Jerry Newman labeled “Monkin’ the Blues.”4 It isn’t a blues, and if it was a Monk original we will never know because the over nine-minute recording doesn’t include the melody. Newman catches Monk in the middle of his solo at the beginning of the bridge. What Monk plays underneath Joe Guy owes a debt to Count Basie, who would play his own two- or three-note “shout choruses” behind his horns. The first of these phrases consists of two alternating notes F# to F, or the augmented fifth to the perfect fifth. Later in the song he creates a funky, bluesy little phrase alternating between Db and Bb—again reminiscent of Count Basie. By imposing a minor third interval over an implied major seventh chord, Monk not only evokes the blues but generates some dissonance.