All five living former U.S. Presidents — Barack Obama, George W. Bush, Bill Clinton, George H.W. Bush and Jimmy Carter — were in attendance for Saturday night (Oct. 21)'s Deep From the Heart: The One America Appeal, a special concert for hurricane relief efforts held at Reed Arena at Texas A&M University in College Station, Texas.

The concert featured a variety of musicians, including Alabama, Lyle Lovett, Robert Earl Keen, Cassadee Pope, Sam Moore and Yolanda Adams. Singer Lee Greenwood was emcee for the event.

The big surprise of the night was an unbilled appearance from pop superstar Lady Gaga, who posed with the presidents for her Instagram account, and received a standing ovation from the audience for her three-song performance.

President Donald Trump was not in attendance, but he thanked the former presidents in a taped message for their "tremendous assistance."

"This wonderful effort reminds us that we truly are one nation under God, all unified by our values and our devotion to one another," he added.

As of Saturday evening, more than $31 million was raised from more than 80,000 donors, according to CNN (Lady Gaga herself says she has donated $1 million to the cause). Funds collected through concert ticket sales will be distributed through various organizations in Texas, Florida, Puerto Rico and the US Virgin Islands.

You can watch the full concert up top, and donate directly at the OneAmerica site.

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