As a hobby music producer I just can't wrap my head around the logic behind copyright infringement. It's so arbitrary. It's illegal to steal a melody but sophisticated chord progressions are fine. It's illegal to copy the text of even the simplest verse but reverse engineering some complex synthesizer sounds is fine. Although I personally strive for it, I don't think originality is a point worth discussing. Music is…
So, what's not to understand? Seems very well defined. Melodies and lyrics are more important than sounds and chord progressions.