"Folk songs are songs for which the original author is unknown - they are inherited from generation to generation, from generation to generation, and from one person to another." I copied this sentence, but it's perfectly apt. Their authors did not know the notes, often they could not even write and read, let alone be interested in any rights. However, it is different with Tremp songs, where most of the campfire performers know nothing about the authorship, but they existed and can be traced. I also had no idea until I met Jarka Mottl, Tony Hořínek and others. But they did not claim copyright ... :)