|English: Dominant seventh tritone resolution chords (Photo credit: Wikipedia)|
Many keyboardists feel right at home with simple triads or seventh chords, but run into difficulty when it comes to some of the more sophisticated, "jazzy" harmonies in "big band" and contemporary music. Where do these sounds come from and how can they be used? Here's a way to think about these sounds and a simple technique you can use to spruce up any harmony with them.
Let's begin with one of the most basic chord progressions in both pop and classical music: V7 - I. In the Key of F, this would represent a C7 chord moving to an F chord. Are you familiar with this progression? There is no question that it "works." Many people are not aware of why it "works." The answer is "voice-leading." The notes of the C7 chord move smoothly to the notes of the F chord.
This is most apparent if we telescope in on the two notes in the C7 chord which form the interval of a tritone: Bb and E.
The tritone is a very jazzy but unstable interval, and in the C7 - F progression, it finds stability by moving outward - the Bb down to A (the third in the F chord), and the E up to F. This resolution is pleasing, and it gives the progression a strength and inevitability. (BbE to AF)
The same two notes, called by the names A# and E, occur in the F#7 chord, which is the V7 of B. Here, though, the notes of the tritone move inward to find their resolution in the notes of the B chord.
(A#E to BD#)
The fact that our tritone interval can lead strongly in either direction makes possible the art of chord substitution; contemporary players often substitute the F# for C7 and vice versa. (These chords lie opposite each other on the "circle of fifths."
Musicians can make use of the two-sided tritone to add new flavors to old chord progressions. Suppose you were faced with the progression F#7 to B7. Remember, that interval of A# and E can move outward as well as inward. Here the base line moves from F# to B, but the tritone in the right hand acts as if we were playing C7 to F. We have purposely confused the harmonic movement, taking advantage of the vagueness of the tritone. (F#/A#E to B/AF)
Try playing a whole circle of fifths, using this concept. If you keep in mind the idea that each hand is capable of "voice-leading" in its own direction. the result can be refreshing and quite beautiful. To start off, here is a sample using C7 - F7 - Bb7 :
C/BbE to B/AEbF then Bb/AbDG
Article credit: Stuart Isacoff
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