A lot of people use this these days to better understand and remember chord progressions.
While studying music before and during my university studies, I learned them as Roman Numerals to differentiate from the scales and the intervals contained within (more on this later)
But this confuses some people if they don’t know and understand Roman Numbers as well.
So here’s a few charts to help you figure this out… let me know if you have any questions about it…
Most common progressions include 1, 4, 5, and 1 6m 4 5, or 1, 2m 3m, 4, 5…
You can also substitute chords within a key for other chords… like subbing the 2m for the 4, or the 6m for the 1, or the 7d for the 5(7)…
Questions…?!