The piece is in
D♭ major. And I think here it's in
F mixolydian, as both
F7 are in F mixolydian. Also, this part is the end of a phrase and sounds quite finalised before it moves back to the opening phrase which begins on
G♭M7 (chord 4 of D♭). Why does it sound so finalised?
The piece is Merry Christmas Mr Lawrence..