A lot of musicians nowadays have unreleased music. Who owns the rights to the lyrics, if anyone? What if someone took those lyrics and sang and performed them as their own? Does the musician being dead make any difference?
The laws are different everywhere. In a lot of countries (including the USA and Germany) the creator owns the copyright to any creative work of art they produce, as soon as they produce it. There is no need to register a copyright, but this does make proof of infringement much easier. If someone takes the work and performs it as their own, that would be copyright infringement. If a creator dies then their heirs inherit the rights. Mostly these rights expire after a set time, often seventy years after the death of the creator.