With each musical mood swing, he’d ask himself the same question: “Is there some way I can imagine a life experience where I would have ended up liking this?” There were glam kids, skinheads, ravers who were into electronic music. Working in the Newbury Comics warehouse, the employees took turns controlling the boombox. “He was always curious, a really good listener,” Winquist says. Gloria Winquist, who hired Sanneh to work at Pipeline Records, says she leaned toward country and folk music, while her business partner, Meggan Todd, liked the girl groups of the 1960s. In addition to Newbury Comics, he held jobs at a couple of Harvard Square record stores that no longer exist. It’s the sense of surprise that keeps Sanneh deeply invested in pop music’s endless mutations, detours, and transgressions. “He’s just a ‘more’ version of what he was then. “Honestly, I just feel like he’s a more global version of this kid I knew in Cambridge, who seemed to know everything to me even then,” he says.

These days, Rudder gets a kick out of watching his old friend in his appearances on “CBS Sunday Morning.”

They all did that, he says, “but no one else was really able to put into words why it was cool, or why it even mattered.” Sanneh “definitely helped me with my own personal critical sense.” Rudder went on to cofound the indie band Bishop Allen he also cofounded the online dating platform OkCupid. “We all defined ourselves by the music we listened to,” says Christian Rudder, who was a close friend of Sanneh’s and a fellow punk-oriented DJ at WHRB, Harvard’s radio station. That something turned out to be the theology of pop music.

“I inherited some of that sense,” says Sanneh, who served during his time as an undergrad as a deputy editor of Transition, the journal on race and culture brought to Harvard by Henry Louis Gates Jr. He was calling for people to rethink their knee-jerk hostility to the project of mission.” The late Lamin Sanneh taught Christianity’s world history “at a time when there was a lot of academic skepticism. “My father in his own way was not afraid to take a position outside of academic consensus,” Sanneh says. Is Lil Nas X’s “Old Town Road” a country song? Does hip-hop have to be political or philosophical to be “good”? Why was disco’s massive appeal so abruptly short-lived? Is it the bluesy bluster of Grand Funk Railroad, or the androgynous power ballads of the hair-metal band Poison, or the scabrous grunge of Nirvana? Could any of those bands have anticipated the variations that followed? “What does it mean to be a rock band? What does rock sound like? How does rock define itself?” “I wanted to tell the story of these genres - and by genres, I kind of mean communities - how a lot of times these communities are defined by arguments,” he says. Kelefa Sanneh (center) and a couple of friends on the T in 1994.

Sanneh kelefa