Towards the end , there seems to be a sort of walk up from the 2 chord to the 5 (so 2 - 3 - 4 -5 in fact)chord and i was wondering if someone could confirm/explain how this work and the logic behind the choice of chords (that would help me applying to other keys)
Here are the chords being used there:
D / Ab-C-D-F (2) =
Dm7 (b5)E / G-C-E =
C/EF / Ab-C-D-F =
Dm7 (b5)/FG / G-C-E (5) =
C/GThe logic behind the choice of chords here is mostly experimentation and sound. Someone was looking for a certain sound and experimented with chords until they found something they liked. The theory can explain what the chords are, but it can't tell you exactly how these chords worked out like this. Since they do work, just take it and run with it, LOL.