Today whatever can be represented visually or in sound can be easily converted to digital form. Once in digital form, it can be stored, copied, and distributed at practically no cost. I hear a story and retell it to my kids. I hear a ballad and play and sing it to other audiences. I hear a tune, whistle it, sing it, play it on a variety of instruments, improvising along the way.
Someone hears that and does likewise.
We need to remember that the human brain is the ultimate storage and retrieval device for books and music and that this means of storage and retrieval fundamentally involves interpretation and change. Today, advanced computers can store and retrieve everything that their user sees or hears over the Internet. In the future, your enhanced brain will be able to store and retrieve everything that it sees, reads, or hears. In other words, sooner or later, books and music will be free. The pace of adoption of technology and the speed bumps of legislation can slow our approach to that point.