A DJ will arrive with a unique set, likely with every track custom-made for a given gig.
Selling any records at all will become very-very hard, except for rare hits with outstanding human vocal performance. In music clips, music will be relegated to the position of a movie soundtrack, if not lower.
Obviously for anything sort of focus-y, house music downtempo etc. If we're not already there, we'll probably be there soon, though I am curious if a careful listener will eventually notice the uncanny valley problem there. But pop music I'd say has two problems. 1. There's a je ne sais quoi quality that's hard to replicate, and two I imagine the corpus is just not that big. I mean sure, there's a decently large corpus of pop music, but good pop music? how many hip hop billboard charts have there been a thousand, maybe a few thousand. How do you combine Beyonce, Janet Jackson, Mariah Carey and Whitney Houston into a banger that doesn't sound too much like Beyonce', Janet Jackson, Mariah Carey and Whitney Houston without the titular character marketing said music.
On top of that, music was not a commodity back then. Live performances literally made a living for many of them as these performances were the only source of music. (And a church needs this music for every mass, for instance.)
Now music is abundant, recordings are cheap / free, and the best performance is easily available in a recorded form. Live performances are still a thing and still feed many of the music creators. Royalties, too. But you better be a superstar for that to bring enough. (Liszt and Mozart were superstars, in a sense.)
Wait until a Dall-E equivalent for music emerges though.