Minor Block Chords / Barris Harris Method . Alternate between inversions of C Em G A and D F A C. Play in locked hands style, hands always touching. Melody note on the outside.
See that we can think of the block chords as being drawn from the bebop scale! For example, C E G A comes from C (D) E (F) G (Ab) A! So, this also avoids the 'dissonance' of 'C E G B'.