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Just as traditional chords in western music are formed by stacking thirds above the tonic major or minor scales, chords can be derived by stacking 4ths above the tonic scale. By adding 4ths to the C Major scale below chord triads are formed. In this case the chord triads have no 3rds which means that they are neither major or minor type chords. The 7ths however indicate whether the triads are major or dominant in nature.

In the next example we have added another 4th interval above the triads. This note is the interval of a Tenth above the tonic, however as a Tenth is just a Third up an octave we will treat these notes as Thirds, which will now enable us to determine whether the chords are major or minor in character.

Chord DegreeFormulaChord Type
Chord 1 1 4 7 3 Major 7 add 11
Chord 2 1 4 b7 b3 Minor 7 add 11
Chord 3 1 4 b7 b3 Minor 7 add 11
Chord 4 1 #4 7 3 Major 7 add #11
Chord 5 1 4 b7 3 Dominant 7 add 11
Chord 6 1 4 b7 b3 Minor 7 add 11
Chord 7 1 4 b7 b3 Minor 7 add 11

Examples of 4th Chords