Intentionally copying the work of someone else, letter by letter, with the goal of getting some kind of reward, can be seen as morally wrong. But from there do

Intentionally copying the work of someone else, letter by letter, with the goal of getting some kind of reward, can be seen as morally wrong. But from there down you have a lot of shades of gray, can seven musical notes be taken as plagiarism if you do a different song with a sucession of notes that you didn't know from where they came (for you may be indistingishable from your own creation), or that you never heard before? Or a full phrase, in a different context, or a "common sense" algorythm to solve a common problem with not so many ways to solve it? When you are not doing a full copy, at some point you reach the level of meme transmission, something that makes us humans, enabled the emergence of civilization and let us to stand on the shoulders of giants. Or worse, with just independent, but similar enough, work, putting laws penalizing that turns creation into a potential trap for whoever that doesn't have an army of lawyers already.