This chord is played start on fret 3 Minor seventh chord with added 13th (6th). Most of the time the 5th is left out (3rd note). The 13th = 6th 13th is used when the chord is a 7th chord with added 6th 6th chords are not 7th chords with added 6th.
Scale structure: R-m3-5-m7-13
Note: C Eb G Bb A
Alternative names: Cminor13, Cmin13, Cm7/13, Cm7(add13), C-7(add13), C-7/13, Cmin7/13, Cmin7(add13), Cm7/6, Cm7(add6), C-7(add6), C-7/6, Cmin7/6, Cmin7(add6)
Importance: Rarely used