COLLEGE STATION, Texas — All five living former U.S. presidents put divergent politics aside and converged on Saturday inside a college sports arena here to raise money and awareness for hurricane victims in Texas, Florida, Puerto Rico and the U.S. Virgin Islands.

"We’ve seen the spirit of America at its best," former president Barack Obama said, "when ordinary people step up and do extraordinary things."

Democrats Obama, Bill Clinton and Jimmy Carter joined Republicans George H.W. and George W. Bush on stage during a rousing concert that set politics aside to promote their joint venture in raising money for those battered by Hurricanes Harvey, Irma and Maria.

The "Deep from the Heart: One America Appeal Concert" also featured performances by country music band Alabama, Rock & Roll Hall of Famer "Soul Man" Sam Moore, gospel legend Yolanda Adams and Texas musicians Lyle Lovett and Robert Earl Keen. In the middle of the concert, the former presidents urged those watching inside the Reed Arena at Texas A&M University and online on YouTube to help those hit by the storms.

A website accepting donations, OneAmericaAppeal.org, was created with 100% of proceeds pledged to hurricane relief. The group, started shortly after Hurricane Harvey hit South Texas in August and expanded to help victims of other disasters, has so far raised $31 million.

"There's still work to do," Clinton said. "It can be a new beginning if we just do what we ought to do and prove that the heart of America, without race or religion or political party, is greater than our problems."

The event opened with a large screen showing dramatic footage from the disasters: Hurricane Harvey slamming into Texas; rescues of flood victims in Houston; Hurricane Irma tearing apart homes in Florida and the U.S. Virgin Islands; swaths of destruction left behind by Hurricane Maria in Puerto Rico.

The five ex-presidents then took to the stage to the cheers of the crowd, all of them standing except for George H.W. Bush, who at 93, has a form of Parkinson’s disease and uses a wheelchair for mobility.

Moore sang standards such as "Battle Hymn of the Republic" and "Soul Man," as the ex-presidents, seated in the front row, clapped and bobbed their heads to the music.

Though rare, the gathering of former U.S. commanders in chief has occurred before, most recently in 2013, when all five met for the opening of the George W. Bush Library at Southern Methodist University, while Obama was still in office.

Conspicuously missing from Saturday's event was President Trump. Last week, George W. Bush and Obama gave speeches in unrelated appearances that sounded like pointed rebukes to the current president, without mentioning Trump by name. It was unclear if Trump was invited to join the concert.

Trump did appear Saturday in a two-minute videotaped statement, where he praised each of the five former presidents by name for their role in helping hurricane victims and pledged his support for those affected by the storms.

The concert took place inside Reed Arena at Texas A&M University, home to the presidential library of the elder Bush. George W. Bush was Texas governor before leaving for the White House and now lives in Dallas.

One of night's more powerful moments came when Lady Gaga emerged on stage as a surprise guest to the roar of the crowd. Dressed in all white, the famed performer sat alone at a white piano and sang solos as the former presidents smiled and clapped nearby.

Lady Gaga announced she was donating $1 million to hurricane victims and urged organizers to help victims recover from mental trauma caused by the disasters, as well as repair broken homes and communities.

"This is a historical moment," the singer said. "We are truly one nation under God."

This wasn't the first time former presidents joined forces for post-disaster fundraising. George H.W. Bush and Clinton raised money together after the 2004 South Asia tsunami and Hurricane Katrina the following year. Clinton and George W. Bush combined to seek donations after Haiti’s 2011 earthquake.

When former presidents get together, they create a viable force for raising awarness and funds for disaster relief and send a powerful message to the rest of the USA, said Jeremi Suri, a University of Texas at Austin history professor and author of The Impossible Presidency: The Rise and Fall of America's Highest Office.

"It shows people hurricane relief is not about being a Democrat or a Republican," he said. "It's good for this country that these people are getting together and trying to bring attention for hurricane relief."

Hurricane Harvey slammed into Texas’ Gulf Coast as a Category 4 hurricane on Aug. 25, unleashing historic flooding in Houston and killing more than 80 people. Shortly thereafter, all five ex-presidents appeared in a commercial for a fundraising effort known as “One America Appeal.” In it, George W. Bush says, “People are hurting down here.” His father, George H.W. Bush, then replies, “We love you, Texas.”

Hurricane Irma subsequently hit Florida, followed by Hurricane Maria in Puerto Rico, while both affected the U.S. Virgin Islands. Organizers expanded the fundraising campaign to help those storm victims, too.

Follow Rick Jervis on Twitter @MrRJervis

Contributing: Associated Press