The changes
The hands
Left hand then right, as the source writes them. A pianist's voicing routinely carries a colour the chord symbol does not spell — a flat ninth over a dominant, a ninth on top of a seventh chord — so the notes printed under each keyboard are what is actually played, rather than what the symbol alone would predict.
Cmaj7
chord 1
LH C2 G2RH E4 B4 D5
B7
chord 2
LH B2 F#3RH D#4 A4 C#5
Bb7
chord 3
LH Bb2 F3RH D4 Ab4 C5
A7
chord 4
LH A2 E3RH C#4 G4 Bb4
Abmaj7
chord 5
LH Ab2 Eb3RH C4 G4 Bb4
G7
chord 6
LH G2 D3RH B3 F4 A4
C
chord 7
LH C1 C2RH E4 G4 C5 E5
Big final chord