How much of that is technological copying/distribution? The printing press caused an explosion of bible and other book/flyer distribution, including an amazing new (at the time) work called "the novel". And that's even without copyright type protections.

And music was always available, we just don't know as much about popular music from the old days because documenting it was hard, and the church (major source of writing) sort of focused on the music written by and for it...