...that's because I to IV is the same relationship as V-I.

Hence I (in C is CEG) + 7 =CEGBb, the Bb wants to resolve to the 3 (A) in IV (FAC)

Or:

I (in G is GBD) + 7 =GBDF, the F wants to resolve to the 3 (E) in IV (CEG)

Cycle of fifths again.

It still sounds crap

EJ