Pliable said ...
Beethoven is black
THAT'S what I was thinking of.I remember the publicity around that book. Even Charles Schultz mentioned it in Peanuts.
Lucy is reading an article to Schroeder (who is of course playing his toy piano while Lucy leans her head on the back)
about Beethoven being black. Schroeder replies : "you mean to tell me all these years I've been playing soul music?"
Peanuts by Charles Schultz, July 7, 1969