40 Isolated Chord Progressions - Chad Lefkowitz-Brown

[n00blar]

https://www.noteflight.com/scores/view/31fb645efa6c879a887b19db8b2447c0f48f88f9

https://www.jazzlessonvideos.com/product-page/secret-to-memorizing-jazz-standards

https://m.youtube.com/watch?v=Vq5EvyPsgCU

40 Isolated Chord Progressions (16)

1. Progression #1 - Unknown Composer
2. Progression #10 - Unknown Composer
3. Progression #11 - Unknown Composer
4. Progression #12 - Unknown Composer
5. Progression #13 - Unknown Composer
6. Progression #14 - Unknown Composer
7. Progression #15 - Unknown Composer
8. Progression #16 - Unknown Composer
9. Progression #2 - Unknown Composer
10. Progression #3 - Unknown Composer
11. Progression #4 - Unknown Composer
12. Progression #5 - Unknown Composer
13. Progression #6 - Unknown Composer
14. Progression #7 - Unknown Composer
15. Progression #8 - Unknown Composer
16. Progression #9 - Unknown Composer

 

[engelbach]

Am I missing something?

Why are 16 unattributed chord progressions labeled "40 Isolated Chord Progressions"?

Why the discrepancy in the numbers and what are they "isolated" from?

Cheers,
Jer