To me, RDJs music always stood out as having uncanny, unique melodies and harmonies. As a teenager I fantasized about him being some sort of benevolent alien music shaman, beaming melodies onto our planet.
Stuff on SAW II where you can't figure out if you're hearing single notes or mutating chords and everything is near-synaesthetic bliss. The wistful otherness of 'Italic Eyeball'. Whatever 'fingerbib', ICBYD, and things on Melodies from Mars are doing was very formative to my 16 year old brain.
It's clear that whatever he does, he channels some unique creative juices.