Well, I think one good thing we can conclude from the music world is that there are people out there who want to pay for humans to do things even when the computer could do it better. I.e. when you go to Vegas and go to a bar, you want to have a guy playing piano and singing, and are willing to pay a bit more for that. You don't want just a jukebox, even if the jukebox can play "Don't Stop Believing" better than the dude with the piano.
All that to say, there will be certain jobs that people will want to pay humans to do even if the robots can do those things "better".
The big weakness of the analogy from the OP is that music is universally accessible, while high level mathematics is not. The potential audience for the human playing the piano is far larger than the human solving complex mathematical theorems.