1-5-1.
6th chord change barry harris method.
secondary dominant.
7th AXIS180=6th change and 9th.
root change to half note up diminish chord and 5th to half note up=half up m6.
bass root and 5th no change.
m7=1357
△7＝9357
change 6th chords play any key, all chords 1 type chords of minor chords,m6,m7,m7b5 chord.
m7=m7+M7
m6=7th chords
m7b5=m7b5
