Moments before [artist id="1236911"]Beyoncé[/artist] took the stage to sing for the Obamas' first dance, [article id="1603090"]the president[/article] asked the crowd, "How good-looking is my wife?" and launched into a brief speech about the significance of the Neighborhood Ball and the role neighborhoods played in his election.

Beyoncé, in a lavender satin gown, serenaded the couple as they shared a few laughs and quiet conversation during the dance. By the time the song was over, B and the Obamas were all in tears.

The song Beyoncé sang, of course, was [article id="1602946"]Etta James' "At Last."[/article] While the song has certainly taken on a new significance this year, it's got [article id="1602971"]quite a history[/article].

"Interestingly enough, the year Etta James made this song popular, 1961, is the year Barack Obama was born," Greg Johnson, blues curator and associate professor at the University of Mississippi, told MTV News.

He added that he can't be sure as to Beyoncé's reasons for picking the song, but he is willing to take a few guesses. "The title can imply, 'At last the United States has elected a black president,' " he suggested. " 'At last the United States has overcome its past fears of people of mixed race, at last the United States has chosen positive vision over the status quo.' "

Johnson did find a connection that has been evident throughout this entire election -- that youth voters have once again found a reason to be interested in politics. "Another spin is that, 'At last youth may find a connection with politics and become more engaged,' " he said. "Whatever the reason, the song will honor not only the Obama family, but pay tribute to one of our finest blues, soul and gospel singers, Etta James."

Watch "Be the Change: Live From the Inaugural" online now, and come back Thursday for the full performances from Kanye West, Kid Rock and Fall Out Boy. Stick with us for wall-to-wall coverage of the inauguration and of the scenes in Washington, D.C., New Orleans and Kenya.