Isn’t any artist or composer who has a recognisable style effectively plagiarising themselves anyway? Almost every John Williams piece I can think of begins with a perfect interval on an anacrusis, every Duran Duran song sounds like Duran Duran because of Le Bon’s voice, and if I hear a woman on the Radio complaining about her boyfriend to music, I can pretty much know it’s going to be Taylor Swift.
I get briefs to “plagiarize” myself all the time. They send me cues I did last season and am told to “copy” them as close as possible. I always as “why not just use it again”, and am constantly told that they need new material, but make it as close as possible to the old material. LOL. I oblige. If they are using it, who cares….