Chord Theory

The table below lists what notes of the scale are needed to build different chords. All the chord spellings are given in relation to the notes of the major scale, i.e a chord described as 1, 3, 5, b7 means you need the 1st, 3rd, 5th and flat 7th of the major scale to build the chord.

Note that the symbol for flat "b" can also be written as a minus sign "-". Similarly, the symbol for sharp "#" is interchangeable with "+".

Type Symbol Construction
Major   1 3 5
Minor m 1 b3 5
Diminished dim, o 1 b3 b5
Diminished 7th dim7, o 7 1 b3 b5 bb7
Half diminished m7b5, ø 1 b3 b5 b7
Augmented aug 1 3 #5 bb7
5th 5 1 5 bb7
7th 7 1 3 5 b7
Minor 7th m7 1 b3 5 b7
Major 7th maj7 1 3 5 7
Minor/major 7th m/maj7 1 b3 5 7
Suspended 2nd sus2 1 2 5
Suspended 4th sus4 1 4 5
7th suspended 2nd 7sus2 1 2 5 b7
7th suspended 4th 7sus4 1 4 5 b7
Added 9th add9 1 3 5 9
Added 4th add4 1 3 4 5
6th 6 1 3 5 6
Minor 6th m6 1 b3 5 6
6/9 6/9 1 3 5 6 9
9th 9 1 3 5 b7 9
Minor 9th m9 1 b3 5 b7 9
Major 9th maj9 1 3 5 7 9
11th 11 1 3 5 b7 9 11
Minor 11th m11 1 b3 5 b7 9 11
Major 11th maj11 1 3 5 7 9 11
13th 13 1 3 5 b7 9 11 13
Minor 13th m13 1 b3 5 b7 9 11 13
Major 13th maj13 1 3 5 7 9 11 13
7th sharp 9th 7#9 7+9 1 3 5 b7 #9
7th flat 9th 7b9 7-9 1 3 5 b7 b9
7th sharp 5th 7#5 7+5 1 3 #5 b7
7th flat 5th 7b5 7-5 1 3 b5 b7