The president went on to explain his thinking to Jarrett and the first lady, who had yet to read the president’s prepared eulogy, during the helicopter ride. Clementa Pinckney, a black pastor who was killed with eight others during Bible study in a Charleston, S.C., church last month, became one of the more memorable moments of his second term. Mr. Obama was on the Marine One helicopter leaving the White House en route to Andrews Air Force Base for his flight to South Carolina when he mentioned the thought to Michelle Obama and Valerie Jarrett, their close friend and a White House senior adviser. “Why on earth would that fit in?” the first lady said in reaction to the idea, according to Jarrett, who was with the Obamas as they departed the White House aboard Marine One on their way to the funeral in South Carolina. “I don’t know whether I’m going to do it,” he said, according to Ms. Jarrett, “but I just wanted to warn you two that I might sing.” He added, “We’ll see how it feels at the time.” 
 
 Ms. Jarrett told the story at the Aspen Ideas Festival last week in a session with Walter Isaacson, the Aspen Institute president. But even then, President Obama hadn’t made his mind up whether he would in fact sing. And it went over very well.” 
 
 So this time, she said, she knew better than to object and, in fact, in an email on Monday she said she and the first lady “both encouraged him to do whatever the spirit moved him to do.” 
 
 Many who watched him that day noted that he paused a long time before beginning to sing. And she later asked him, “Were you thinking about whether or not you were going to sing?” 
 
 “Oh no, I knew I was going to sing, I was just trying to figure out what key to sing in,” the president said in response to Jarrett.
– President Obama's rendition of "Amazing Grace" at the end of his eulogy for the Rev. Clementa Pinckney has been viewed more than 2 million times on YouTube. Had he listened to the gut reaction of those around him, it might not have happened at all. The New York Times and ABC News have the background on his decision to break out in song: Obama first shared his plan—to sing once he got "to the second part of referring to 'Amazing Grace'"—with Michelle Obama and senior adviser Valerie Jarrett while en route to Andrews Air Force Base to board his flight to South Carolina. "I think if I sing, the church will sing with me," he said, per Jarrett, who told the story during a Q&A at the Aspen Ideas Festival last week. How Jarrett says she responded: "Hmm." How Michelle put it: "Why on earth would that fit in?" Jarrett says he told them he wasn't convinced he'd go that route, but wanted to offer a warning. "We'll see how it feels at the time," she says he said. She says she and Michelle were ultimately encouraging, and as for the long pause before he began, she says that was a moment of debate ... but not about whether to go ahead. "I knew I was going to sing," he told her. "I was just trying to figure out which key to sing it."