• Level 1: Root Position Triads
• Level 2: Substitutes (triadic)
• Level 3: Secondary Dominants (2:49)
• Level 4: Tritone Substitution (3:23)
• Level 5: Different Tritone substitution (3:47)
• Level 6: Different Substitutes (modal?) (4:28)
• Level 7: Substitute for the ONE chord (6:20)
• Level 8: Added note Triads in Contrary Motion (as substitutes) (7:48)
• Level 9: Inner Note Movement (9:19) and Modal Mixture
• Level 10: Polytonal (11:18) or, chord over chord

– Thanks Rory Quirk @YouTube