After spending years working on a documentary about Japanese-Americans incarcerated during World War II, Kishi Bashi joked that he needed something lighter to help with “cleansing my brain of sadness.

“Sly Lives! (aka The Burden of Black Genius)” road tests a theory that its director, Ahmir Questlove Thompson, has had for a while, and that’s articulated in the Hulu documentary by Dream Hampton: ...