At first glance it seems like a crazy hodge-podge of chords. The concluding major chord moving to minor on beat 4 of the next to last measure makes one wonder, is it supposed to be Middle-Eastern? But, apparently it's from Miles' modal period, so let's do a quick analysis and determine a best approach to playing this captivating tune.
My guess is that it's in Phrygian mode, based on iii of the key. The move from iii to IV, measures 1-2 is reminiscent of "The World Is A Ghetto" by pop R&B group War. The VII chord in bar 3 is V of iii, with the I chord of the key sounding a lot like bVI of the iii chord in measure 4. Then 5 through 8 are still modal: vi-IV-III-iii. The major III chord in bar 7 is a classic use of a "surprise chord."
The bridge is vi-IV-vi-IV followed by ii-ii/V-I-IV. Another way to characterize the whole song would be to treat the Phrygian iii (which serves as a tonic) as though it were a minor i. Normally, it's preferable to think of minor key pieces in relation to their relative major because one rarely encounter unfamiliar progressions as minor harmony often transits to relative major. But just for fun, here's how Nardis translates if we make the Phrygian chord our root i:
i-bII-V7-bVI iv-bII-I-i (rpt. 8)
bridge: iv-bII-iv-bII bvii-bvii/bIII7-bVI-bI
Treating iii of the key as if it were i introduced a minor bvii and several awkward chord shifts that don't confront us if we just relax and play in the key. After all, that's what modal is all about!
The rhythmic punches throughout the tune are very important for underlining the melody. Don't make it too complicated - a slow count, 2 beats per measure makes the quarter note anticipations into simple upbeats, and eighth note anticipations are simply a small omission from sixteenth note patterns. There's a triplet figure on beat 1 in bar 7 that could also be thought of as a quarter note shake or "turn" - helping us realize that measure 7 is merely a basic quarter-half-quarter syncopation, or eighth-quarter-eighth if counting in cut time.