See Lady Gaga Perform, All Five Former Presidents Unite at Hurricane Benefit

Singer performs solo piano renditions of "Million Reasons," "You and I" and "Edge of Glory" at One America Appeal event in Texas

All five living former U.S. presidents united onstage and Lady Gaga made a surprise appearance to help aid hurricane victims for One America Appeal.

All five living former U.S. presidents – Barack Obama, George W. Bush, Bill Clinton, George Bush and Jimmy Carter – united onstage together to help raise funds for hurricane victims as part of Saturday's One America Appeal event, which featured a surprise appearance by Lady Gaga.

"The heart of America, without regard to race or religion or political party, is greater than our problems," Clinton told the audience at Texas A&M University.

Donald Trump did not attend One America Appeal, which raised over $31 million, instead offering a video message, "To Presidents Jimmy Carter, George H.W. Bush, Bill Clinton, George W. Bush and Barack Obama, Melania and I want to express our deep gratitude for your 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."

Lady Gaga made an unannounced appearance during One America Appeal at the 1:50:25-mark of the event. "Now that's what I call an audience," the singer said, looking down at the former presidents.

"The most special thing of all is how pain is such an equalizer and in a time of catastrophe we all put our differences aside and we come together," Gaga added. "Because we need each other, or we can't survive."

Gaga then delivered into a solo piano rendition of "Million Reasons" – "It's about pain, and sometimes life gives us a million reasons why to give up, but we stick around," Gaga said of the Joanne song – along with a "You and I" that featured Gaga singing to each president and "The Edge of Glory."

The singer also revealed that she donated $1 million to the victims of Hurricanes Harvey, Irma and Maria.

Gaga later tweeted a photograph of herself with the five former presidents: