Saying that artists shouldn't appropriate from other cultures seems deeply flawed. Most obviously, it relegates everyone except rich North American/Europeans to the world music bin. It's inherently chauvinistic. Nobody thinks that non-Europeans are doing anything wrong when they wear European style clothing or adopt European music. Why the asymmetry? The only reason I can see is that the Europeans think they should be held to a higher standard than lesser peoples. Both of the items of clothing Bob Marley is wearing in the illustration are adopted from the US and most of the instruments his band used are of US or European origin, as was the language he spoke. But that's OK because we're talking about nobless oblige here. These rules only apply to the big, important people. The self-importance is jaw-dropping. People from those other cultures don't consider themselves weak and second rate, in need of protection. They rightly consider themselves serious players in the world culture, entitled to be part of the rough and tumble.