Major 6th and Minor 6th chords
Major 6th chord : Root – major 3rd – fifth – major 6th
Minor 6th chord : Root – minor 3rd – fifth – major 6th
The major and minor 6th chords have the same 6th note – the major 6th.
The difference between major 6th and minor 6th chords is the third note.
The minor and major in the name of the chord points to the kind of 3rd note and not the 6th note. Adding the major 6th note to a major or minor chord gives us the major 6th or minor 6th chord respectively.
#5 or b6 – the minor 6th note
When we find '6th' in a chord name, it usually refers to the major 6th note.
The minor 6th note when used in chords, is usually named as #5 or b6 and is present in chords like augmented, major #5, b13 etc.
13th note : 6th note + 7
13th note and the 6th note are the same note. With C as root, the 13th note is A, which is same as the 6th note.
13th chord is a 7th chord + the 6th note. when possible (guitar has physical limitations limits the number of notes that can be played at the same time) play both 4th and 2nd notes.
13th chord : 7th chord + 6th note + 4th note + 2nd note
b13th (flat 13th) note is same as the b6th (flat 6th note), the minor 6th note.
More about numbers above seven in chords.
Instead of the third note in a major or minor chord, if you play the 6th note, you get a suspended 6th chord.
For example if we want the Csus6th chord, start with a C major or C minor chord.
C major chord : C E G (root – major third – fifth)
C minor chord :C Eb G (root – minor 3rd – fifth)
A is the 6th note for C root.
Instead of the third note – E or Eb – in the above chords, play A note to get Csus6th chord : C G A
Diminished seventh chord and minor 6th chord
C minor 6th : C Eb G A (root – minor 3rd – fifth – major 6th)
C diminished seventh : C Eb Gb A (root – minor 3rd – flat fifth – major 6th)
Flattening the fifth note of a minor 6th chord gives us the diminished seventh chord for the same root.