George Gershwin visited African-American churches and nightclubs in South Carolina to craft the music for “Porgy & Bess.” Years after his death, the opera and its all-star cast played an unexpected role in Cold War relations.

Everybody knows the Beethoven story: He’s a brilliant composer who faced hearing loss; a genius who couldn’t listen to his own masterpieces. But there’s a different way to consider the story we think we know.