2.2.3 Tritone/4ths chords
Made up of a perfect fourth over a tritone interval, they are akin to quartal chords but have even greater harmonic potential. A tritone/4th voicing is capable of expressing at least 8 harmonies. Here is a list with A7 13 as the point of departure:
1 2 3 4 5 6 7 8
G C# F# can be: A 7 13 Eb- 6 9 E, G, Bb, Db dim Bb #9 13 b13 Eb 7 #9 Db- 7 b5 11 F b9 9 b13 F# b9
with bass: A Eb E, B B E F F F#
Tritone/4th voicings have a smart, jazzy sound due to their open configuration, the tritone, the fourth and the halftone friction between the top and lowest note. Their salient feature is that a half-step slide up or down moves the harmony 1 step up or down in the Circle. One-half step slide moves 1 step up or down the Circle:
A cadence in F:
Note the first 2 entries in the preceding page's list: the same tritone/4th voicing can stand for II and V7, here E- , A7 with basses E and A, respectively.
With a tritone/4th voicing in the left and 2 fourths in the right hand, one and the same chord stands for II7 (11) and V7. Bottom notes are 3rd and dominant-7th, respectively. Hear it with basses C and F. Truly minimal motion!
Another great feature of the tritone/4th voicings is that with a parallel slide half-step up or down they switch between the key's minor and major mode, here shown in the left hand:
Lowest note is the 3rd.
Another parallel half-step slide of tritone/4th chords toggles between diminished and dominant-7th of the same key, but now the lowest note is the 7th:
This leads to the third entry in the list: tritone/4th voicings can be diminished chords. In diminished harmony, everything repeats every minor3rd step (see Part 2, section 5).
Therefore tritone/4th voicings played with their lowest notes a minor 3rd apart (plus an octave), or a multiple of 3rds apart, render spicy diminished chords:
The hands' movement need not be parallel:
See Part Two, Chapter 5 for more on tritone/4th voicings in diminished harmony. Tritone/4ths are truly magic voicings. Bill Evans favored them in his playing.
4) || / I7 Idim IIØ | I7 || with variation I bIII6 II7 bIImaj7
These are blues clichés, concluding phrases. The last one is a turnaround | I VI II V | I.
(5) | II7 Idim | I |
A finishing lick introduced by Count Basie
(6) | I I7 IV #IVdim | V7 This is a famous turnaround cliché with its ascending bass line:
(7) | I-/I I-/VII | I-/bVII I-/VI | "Descending Bass" The descending line C B Bb A embellishes the C chord. It can be stretched over two bars or fit into one. It occurs in many titles such as In a Sentimental Mood, It Don't mean a Thing ..., My Funny Valentine, Feelings, and, in major key, Strings of Pearls.
It can be applied to II7--> II as well, here A7 13 --> A+ --> A7:
Diminished Voicings
The next figure shows on each quarter beat the same voicings as in the previous figure, here played in one hand. On each following 1/8 beat the chords "resolve" to basic triads:
The following is the same concept with the voices distributed between the hands:
In the next figure the right thumb plays the roots, the left hand plays the tension tones:
Interpreting these chords as X7 b9, the first bar is F, Ab, B, D7 b9, the second is G, Bb, Db, E7 b9, the third bar is C, Eb, Gb, A7 b9. Each group of diminished chords is enharmonic to a group of V7 b9 chords one step away in the Circle: Diminished Group C D (F) G
V 7 b9 Group F enharmonic to
G C
In the next figure, the upper 2 voices trace halftone-wholetone scales. The RH thumb plays minor 3rd intervals. RH chord shapes are triads in 1st and 2nd inversion:
II V I progression
Starting with a tertial II7 chord
