Now I've heard there was a secret chord
I will die on the hill that this so-called “secret chord” is nothing more than a vanilla V7.
“It goes like this, the 4th the 5th”: Scale degrees.
They are the root (5th scale degree) and minor 7th (4th scale degree) of the V7.
“The minor fall and rhe major lift”: Classic western harmony.
The minor 7th of V7 resolves by descending to the 3rd of the I (or i).
The major 3rd of V7 (the leading tone) resolves by ascending to the tonic.
This is unambiguous as the V7 consists of the root, the major 3rd, the perfect 5th, and the minor 7th.
This is one of the all time great songs about *******.