Did John Steinbeck steal from the Book of Genesiswhen he wrote East of Eden? Was it plagiarism when the Coen brothers made O Brother, Where Art Thou?, having shaped the story around Homer’s Odyssey? And was it stealing when Darius Rucker covered “Wagon Wheel”? Or, for that matter, was it plagiarism when Bob Dylan recorded a demo using lyrics and tropes from decades-old blues songs?