Inheritance is very relevant in those special fields where a regulated compensation scheme exists in parallel to the sale of usage rights (literature and musical scores). The organisations that are responsible for distribution are kind of notorious for being dominated by heirs. Unsurprisingly, because current creators create, whereas heirs focus all their energy on maximising the harvest.
Another implication that occasionally comes up to freak everybody out is that there is some legal basis for creators to have a word in changes to their work, which can be a total PITA for organizations that once commissioned a building from a famous architect who left assertive offspring.
I was wondering this as well, I did some digging. It's really interesting actually, it doesn't seem that Germany is that much of a veteran when it comes to copyright (In the early 1900's they virtually didn't have any copyright law in place).
To your question, yes you can inherit something from your grandmother. Inheritance is designated by the original author, and enacted in the event of their death (As far as I can tell).
Another implication that occasionally comes up to freak everybody out is that there is some legal basis for creators to have a word in changes to their work, which can be a total PITA for organizations that once commissioned a building from a famous architect who left assertive offspring.