NEW YORK – At 93, singer, actor, humanitarian and activist Harry Belafonte has led a richly gratifying yet challenging life, often at the center of the nation’s more consequential events and profound struggles. Yet, "The Sit-In: Harry Belafonte Hosts the Tonight Show" focuses on one largely forgotten week from Belafonte's storied career.

Directed by Yoruba Richen, the engaging and surprisingly topical 75-minute documentary premieres on the Peacock Premium streaming service Thursday, Sept. 10.

The film's title derives from a phrase the singer used in an ad in the showbiz trade journal Variety that he took out to thank "The Tonight Show" host Johnny Carson, the program’s producers and the guests who appeared with him "for letting him sit-in" when the actor substituted for Carson Feb. 5–9, 1968.

Against the backdrop of the Vietnam War and the protests, racial strife and social upheaval that characterized that fateful year, Belafonte became the first African American to host a late-night TV show.

Notable commentators include comedian, actress and TV host Whoopi Goldberg, Bill Carter, author of "The War for Late Night," and former NBC journalist Tamron Hall. Her interviews with the nonagenarian activist represent a great asset for "The Sit-In."

Belafonte said "The Tonight Show" was, "a powerful platform." But "we had to do more than sing," he continued. "We had to have a point of view and speak out."

Belafonte wanted to showcase "the best Black America had to offer." The episodes featured well-known African American performers such as comedian Nipsey Russell, actress-singer Diahann Carroll, Queen of Soul Aretha Franklin and more obscure artists such as folk singer Leon Bibb.

Belafonte's close relationships with the Rev. Martin Luther King Jr. and Sen. Robert F. Kennedy facilitated their separate appearances, which, more than anything else, distinguished the shows during the activist's brief run as host.

Of Rev. King, Belafonte said: "Listening to the things he had to say I knew I'd be forever in his service." Sitting alongside 42-year-old actor Paul Newman, the civil rights leader revealed a sense of humor the public had rarely glimpsed.

Describing a recent bumpy air flight, Rev. King said: "It isn’t that I don’t have faith in God in the air, it's just that I have more experience with him on the ground."

Belafonte's relationship with Kennedy was complicated and evolved over time. As U.S. attorney general, Kennedy had authorized the FBI's wiretapping of Rev. King. Belafonte's relationship to Kennedy "had been adversarial until Bobby made the choice to learn more about the plight" of poor and Black people.

Encouraged by Kennedy’s commitment to lifting people out of poverty and his desire to end the Vietnam War, Belafonte hoped Kennedy would use his guest spot to announce his presidential campaign – for which the host would eventually work.

Contemporary viewers will be painfully aware that assassins' bullets took both men's lives mere months after their guest spots. Rev. King, who was murdered April 4, was 39; Kennedy, who died June 6, was 42.

A sense of tragically ironic foreboding especially hangs over Rev. King's appearance. "39; you're a young fellow," Newman said. And Belafonte asked his guest: "What do you have in store for us this summer?"

Both deaths, Belafonte said, "left a void," one from which neither he nor the nation has yet recovered.

With only one swear word spoken, "The Sit-In" makes suitable viewing for adults and teens, especially given its educational value for the latter group. Its grim themes, however, make it less than appropriate fare for little kids.

"The Sit-In" struggles to find its footing, in part because it was originally difficult to obtain archival footage of the Belafonte shows. Before 1971, NBC taped over programs. But an archivist named Phil Gries found audio recordings, which helped the documentarians.

Even so, Belafonte's reflections alone are rewarding enough to justify viewers' investment of time in the program. Those tuning in may not agree with him on every issue, but they will undoubtedly appreciate the way "The Sit-In" honors Belafonte's lifelong commitment to civil rights.

Byrd is a guest reviewer for Catholic News Service.