Let's consider Louis. How many trumpeters (and cornetists) have based their styles upon him, from Harry James to Doc Severinsen to Ruby Braff ? I don't know about Ruby, but the other two certainly made a lot of money. And certainly collectively, all of jazz and all of music is much more indebted to Louis. Now it isn't just a simple matter of a certain amount per riff that is copied or borrowed. But Louis is the master (at least for these guys), and whereas these others are certain good and great in their own way, in a just world Louis should have been far better off than he was.
Louis was not, and still has not, been given his due. The music and entertainment industry certainly made a great deal money off of him, though, and by that, I mean his musical ideas, obviously. Now did these other guys steal in the individual sense from Louis? No, of course not, they idealized him, recognized him for the giant he was, etc. But they could not help but benefit also from an unjust system and a racist society which would not reward Louis as it rewarded them. Was this kind of reward unjust? To some degree, yes.
But they were tools of this unjust system. Does this make them personally bad? No. Certainly not directly on the individual level. If you move to the case of Goodman, who also benefited, he worked within the system to change it by playing publicly with Lionel Hampton. Others on the forum have also pointed out how popularization by whites of black music led to advances in civil rights.
But those who participate in an unjust system are also thereby unjust at least collectively, particularly if they gain by it.
There are other examples of this kind of thing. It is not isolated to jazz. My grandparents came to this country decades after slavery was abolished. I have never owned slaves, but by being a white American, I have indirectly benefited from an economy that was built on slavery. I am part of an economy that is in this sense unjust, making me unjust (contrary to my own choice).