With my limited, but completely useless, knowledge on the comics, (I'm also assuming that his speed works almost like The Flash's does i.e. Speed Force)
I'm guessing that anything within close proximity to him moves at the same speed as he does. So the music would speed up as he does, but if he was streaming the music from YouTube or something, I don't think he'd be able to listen to it while running.
Bam you're welcome
I'm guessing that anything within close proximity to him moves at the same speed as he does. So the music would speed up as he does, but if he was streaming the music from YouTube or something, I don't think he'd be able to listen to it while running.