One of the big entertainment stories of 2024 has been an early version of Mickey Mouse finally going into the public domain. This means the Steamboat Willy-style Mickey is no longer protected by copyright. All artistic works will eventually become public domain, and that includes rock songs. Once that happens, they’ll become available to everyone without having to pay royalties, just like we have now with, say, a Beethoven symphony.
In most countries, there are rules saying that X number of years have to pass since the death of the last surviving writer for a song to become public domain. Using that as a rough guide, songs from the birth of rock to those recorded in 1972 will become public property on February 15, 2067. That means a lot of Beatles, Stones, Led Zeppelin, and more will become royalty-free.
As for songs recorded after 1972, that all depends on how long the composers will live.