Ok guys, I analyzed the song a little today. Here is what I have concluded:
As far as I can tell; the two first chords are E Dominant 7 and Dmaj.

So; basically the key is A major. But Superhuman is starting on the fifth degree of the scale; thus, establishing an E Mixolydian tonality.
I personally favor two scales over those two chords:
E Dominant Pentatonic [E - F# - G# - B - D]
E Mixolydian [ E - F# - G# - A - B - C# - D]

There is a modulation at the third chord. Superhuman is modulating to the key of A# major, and then returning.
The same modulation appears several times throughout the song.

Thankfully the modulation is long enough that you can try different scales over the A# major chord.
I really like the sound of this Mode:
E Prometheus Neopolitan 4th Mode [ A# - C# - D - E - F - G#]

Have fun guys. :cool:


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