Jennifer Hudson, as is well documented, can crush a cover. Closing out night three of the Democratic National Convention, she rose to the occasion, singing one of the most powerful songs ever recorded, Sam Cooke’s “A Change Is Gonna Come.” It was nothing short of stunning. Hudson performed the song — an anthem in the fight against racism since 1964 — backed by just two pianists and a saxophonist at an otherwise empty Chicago Cultural Center. But it wasn’t really empty, considering how Hudson’s voice resonated through the whole building. Hudson wasn’t the only one to turn to ’60s protest music during the convention; Billy Porter performed an absurd rendition of Buffalo Springfield’s “For What It’s Worth,” backed by the band’s guitarist, Stephen Stills. Just remember: That change isn’t gonna come unless you vote, and, well, if J.Hud’s voice couldn’t convince you just then, you’re lost to us.