7th chords

Seventh chords are constructed using the four odd-numbered notes of a seven-note scale (with exceptions), or by moving up in skips or thirds from any note within a seven-note scale (as in a harmonized scale). The quality of the chord is determined by its comparison to a paralell major scale. If it matches the first, third, fifth and seventh note, it is a major-seventh chord [ maj7, mj7,

7 ]. Alterations from this chord are described in chord formulas, which are used to create chord symbols.

CHORD FORMULA 1-3-5-7 = maj7		CHORD SYMBOL Cmaj7 [ other symbols / chord name(s) ]
b7		C7 [ NA / dominant-seventh (primary blues chord) ]
b3, b7		Cm7 [ -7, min7 / minor seventh ]
b3, b5, b7		Cm7b5 [ -7b5, min7b5 (or) ^Ø / minor seventh flat-five (or) half-diminished ]
b3, b5, bb7		C°7 [ dim7 / diminished-seventh ]
4/3, b7 scale degree 4 replaces scale degree 3		C7sus4 [ 7sus / seventh suspended-fourth ]
#5		C7#5 [ maj7#5 (or) +7, +maj7, aug^(maj7) / major-seventh sharp-five (or) augmented major-seventh ]
b5		C7b5 [ maj7b5 / major-seventh flat-five ]
b3		Cm⁽⁷⁾ [ -(maj7), min^(maj7) / minor major-seventh ]
#5, b7		C7#5 [ 7+5 (or) +7, 7+, aug7, 7aug / seventh sharp-five (or) augmented seventh ]
b5, b7		C7b5 [ NA / seventh flat-five ]