There's a whole industry of "royalty-free music", full of songs you hadn't heard before (or if you had, you'd forget about it anyways), which you can license for a fixed fee that's much lower than either mandatory royalties or negotiating with labels for "branded" (for lack of better term).

Existed for years, nothing to do with AI (though, with AI, you don't even need those).

Google "royalty-free music providers".