NOTE: THIS IS A WORK IN PROGRESS
Copyright laws differ around the world. In some countries it’s not automatic; it needs to be registered. In Canada copyright law automatically covers all creative works.
Copyright law is supposedly intended to privilege the creator, but since it is a monopoly, in reality only someone with the ability to enforce their rights can collect revenues world wide, or even country wide. The Copyright holder has first to discover cases of copyright infringement, and then collect whatever royalties are owed. What this means is that big publishers and record companies etc are the chief beneficiaries.
Among Intellectual Property industries, the music business has traditionally treated creators the worst, which is why Columbia breaking Dad’s deal for his “Play It Long And Lonesome” turned out to be a good thing, because it meant Dad retained copyright to his own works.