The root is a tritone away, but the important thing is that both chords share the inner tritone between 3rd and 7th. Example: G7 is replaced by Db7. An example where this substitution works particularly well is with the II-V-I cadence. So say the original song calls for a C chord, with a certain melody over it. In this case the V is substituted by the chord featuring the same tritone (bII7), which gives way to a chromatic progression on the bass. Tritone substitutions are also closely related to the alt chord used commonly in jazz. Jazz theory explains that we can substitute a dominant seventh chord with another dominant seventh chord that shares the same tritone. Of these, the dominant is the one which wants to resolve itself the most. ex 8d: Incorrect use of tritone substitution, the D in example 1 is perfectly happy resolving down a whole tone to the C, however in example 2 this resolution sounds wrong partly because of a b9 tendency to resolve by a semitone as mentioned, but also due to the conflict with the Db in the root resolving down a semitone to C. Tritone substitution is used for harmonic diversity & contrast, often using altered chords. “Dominant chord” is the name we give to the 5th chord (V7) in a major scale. A tritone substitution is the substitution of a dominant seventh chord with another chord whose root is a tritone (augmented fourth) lower. To understand a "tritone substitution", first you have to understand the engine that drives a normal V7 - I cadence.. Before watching this you should have done the previous lessons in this series - without a solid understanding of Functioning Dominants and Altered Harmony this is going to mess with your head. First and foremost, the tritone is an important part of our harmonic system, which consists of three main functions: the tonic, dominant and subdominant. For example, C7alt is built from the scale C, Db, D#, E, Gb, G#, Bb. Tritone substitution is a very cool jazz chord substitution. A tritone substitution usually takes the place of a dominant (V7) chord. What is a “Tritone Sub?”? A tritone substitution is the substitution of a dominant seventh chord with another chord whose root is a tritone (augmented fourth) lower. A tritone is an interval of an augmented fourth or diminished (flatted) fifth (three whole steps). Attention: Intervals are the building block of chords. So let’s plug in some variables. C & F#/Gb; C#/Db & G; D & Ab/G#; The Tritone in Chords. The tritone substitution for the 5 chord G7 would be Db7. The tritone substitution is a dominant, or secondary dominant 7th chord whose root is a … Tritone Substitution Part XII Replacing a dominant seventh (or a minor seventh) chord by a dominant seventh chord whose root is a tritone away is referred to as a tritone (or flatted fifth) substitution. G7 and Db7 share the same tritone interval which gives both chords their dominant quality and makes these two chords interchangeable.