(L-R) Harry Belafonte, Dr. Martin Luther King, Tony Bennett

*In Harry Belafonte’s recent HBO documentary “Sing Your Song,” the singer/activist spoke about recruiting his famous friends, including singer Tony Bennett, to join him in Alabama to support Dr. Martin Luther King’s historic 1965 march from Selma to Montgomery.

Earlier this month, during a Television Critics Association panel for his PBS special “Tony Bennett: Duets II,” premiering Friday, the legendary crooner took us back to the moment his good friend Belafonte approached him with the request.

“Harry said, ‘I’d like you to go down South with me.’ And I said, ‘How come?’ because I was tired of seeing the insanity of war, which I hated,” Bennett recalled.  “He knew me quite well. We grew up together, Harry and I. And he said, ‘This is different.’ So I said, ‘How come?’ He said, ‘Well, they’re doing horrible things to African Americans.’ And I said, ‘Like what?’ And I don’t even want to say what he told me, but it was so horrible that I said, ‘I’m going with you.’”

Bennett would go on to become a staunch supporter of King and the Civil Rights Movement. And nearly five decades after the Selma march, Queen Latifah and Norah Jones are among the artists who sing with the 85-year-old star in the PBS broadcast of “Tony Bennett: Duets II,” a 90-minute special premiering Friday (Jan. 27) at 9 p.m. that captures the recording of his recent album of the same name. [Scroll down to watch the promo.]

Singer Tony Bennett performs onstage during the Great Performances An Evening With Tony Bennett panel during the PBS portion of the 2012 Winter TCA Tour at The Langham Huntington Hotel and Spa on Jan. 5, 2012 in Pasadena, Calif.

Bennett also performs in the special with Lady Gaga, John Mayer, Michael Buble, k.d. lang, Sheryl Crow, Willie Nelson, Josh Groban, Andrea Bocelli, Faith Hill, Alejandro Sanz, Carrie Underwood and the late Amy Winehouse in her last recording.

In the audio below, Bennett says folks in Europe are still amazed about the fact that America (the one-time perpetrators of slavery) was able to vote a black man into the nation’s highest office.

Watch Tony Bennett: Duets II on PBS. See more from Great Performances.