INTRODUCTION In a 12-Note system, there are 2047 chord types. 165 of them are 4-note sets (43 if you ignore inversions). When it comes to 4-note sets, most of us have heard of 7th chords: 1-3-5-7. Improvising musicians have explored the...

From the introduction: Modes are often at first understood in relation to a parent scale. While this can be helpful as a starting point and for developing muscle memory, in practice it doesn’t always point the player to the right chord...