To clarify - there's an analytical side to this (e.g. songs that actually have the same notes/melodies etc. - requires detailed analysis to do this justice), and there's a side where saying 'these songs have been done before' isn't to be taken too literally The analytical side would show how some songs are derivative (i.e. meaning they actually copy some things in other songs closely enough e.g. 80%), but songs don't have to so strongly resemble others (can be 25-40% similar) to see that the songwriting ideas aren't original or that unique (e.g. vocal melodies aren't that far off from other songs etc.) And it's not just about comparing songs as a whole - look at the sound palettle used or sound design etc. - do they add anything to a listener's experience given what else they could have listened to? (Might depend but also the answer may be no if they've found more creative/unconventional/adventurous/daring elements elsewhere) Off the top of my head, I know the chorus on Invisible sounds like the chorus on FM's "Welcome", Good Goodbye has some similarities to LOITE, Heavy has some instrumental similarities to Lil Wayne's "Mirror" etc. - but to further prove this point I would need time to dig into it (if I listened to music more often though I probably wouldn't need that time since I would have come across music enough times that those similarities would be crystal clear) And no I don't think a song has to be derivative of a different artist in order for it to be derivative.