Evan Puschak, known on YouTube as the Nerdwriter, posts videos dissecting topics from Shakespeare and Tarkovsky to Superman; from Martin Luther King, Jr., and Bernie Sanders to Donald Trump. The videos are complex; he may spend weeks editing image, sound, and written narration. He spoke with the Radio Hour’s Ngofeen Mputubwele about what drew him to the essay form, and how he’s found success online. “The essay is not a treatise. It’s not a term paper. It’s not something systematically covering everything about a subject,” Puschak says. “It is an inquiry. . . . The cool thing about the video essay is that you are seeing these people’s thoughts articulated with a whole new toolbox.” As much as he loves the video form, Puschak is crossing over into print next month with a book of essays titled “Escape Into Meaning.” Plus, the writer Kelefa Sanneh highlights some notable tracks playing on country radio stations this summer.