Minute 42 of episode 411 - https://www.samharris.org/podcasts/making-sense-episodes/411-the-victimhood-pandemic
Sam's full quote:
"I think music, that particular case, I think that's going to fall, pretty soon. I think it's only a matter of - definitely not 15 years - before computer generated music is just going to be demonstrably some kind of super stimulus, where if I present you with 10 new songs of any flavour, whether they be pop songs or symphonies, and ask you which you like better, the machines are going to have worked it out algorithmically to the point where you'll be picking the machines over the humans nine times out of ten."