While Ray's re-harmonization break from the traditional chords, they are soulful, recognizable movements you'd expect to hear from Ray.
But, it's his use of the flat-2 diminished passing chord that makes this harmony really move.
See, here in Eb major, the heart of this progression comes from bass movement from Eb to E to F to Bb.
That note "E" is the secret to Ray's sound. That E natural is outside the key of Eb and creates a chromatic passing tone between Eb (the 1) and F (the 2). The E diminished 7th is the perfect chord for this situation. It's this diminished chord that creates the movement that propels the song forward.
And while Ray's E diminished chord resolves upwards to F, its not always the same F chord. Check it out, he harmonizes it 3 different ways:
The first time, the E diminished moves to Bb with that F in the bass.
Then, the next time through, the E diminished moves up to an F minor 7th, which creates a 2-5-1 back to Eb.
And he even takes this a step further later on with this C7 / E, into F7 to Bb. Changing the chords to dominants, moving around the circle, creates an even more bluesy sound.
(For the nerds: That C7 / E is essentially still E diminished, especially if you add a flat-9.)
Try playing through the changes yourself, and take a look for all the places you find this bass motion.