This is the two bar riff that Stevie's left hand / Nathan Watts are playing:
It goes through the whole of the song.
Bbm9 Gb6(Ab bass) Emaj7(F# bass) Gb6
G:|--------1-3---------------------|--------r-----------------------|
D:|--------------------------------|4-------e-----------------------|
A:|1-1-1-1-----1-1-----------------|--4-1---s-----------------------|
E:|----------------4-4-4-4-4-4-4-4-|------2-t-----------------1-4-5-|
For ease of playing in the recorded key you might want to try the following
(i.e.: tune down a semitone)
Bm9 G6(A bass) Fmaj7(G bass) G6
Gb:|--------2-4---------------------|0-------r-----------------------|
Db:|--------------------------------|--0-----e-----------------------|
Ab:|2-2-2-2-----2-2-0-0-0-0-0-0-0-0-|----2---s-------------------0-1-|
Eb:|--------------------------------|------3-t-----------------2-----|
PLAY TOO ..