Austin - All five living former US presidents will be attending a concert on Saturday night in a Texas college town, raising money for relief efforts from Hurricane Harvey, Irma and Maria's devastation in Texas, Florida, Puerto Rico and the US Virgin Islands.Democrats Barack Obama, Bill Clinton and Jimmy Carter and Republicans George HW and George W Bush are putting aside politics in contrast with President Donald Trump, who has vowed to help Texas and Florida for as long as it takes but has criticised Puerto Rican leaders while suggesting aid there won't be unlimited.Having so much ex-presidential power in one place is unusual. George HW Bush spokesperson Jim McGrath said all five of Saturday night's attendees haven't been together since the opening of the George W Bush Presidential Library in Dallas in 2013, when Obama was still in office. He didn't answer a question about whether Trump was formally invited.Seek donationsThe concert features the 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. It's happening at Texas A&M University's Reed Arena in College Station, home to the presidential library of the elder Bush. At 93, he has a form of Parkinson's disease and uses a motorised scooter or a wheelchair for mobility, though he participated in the coin flip at February's Super Bowl in his hometown of Houston.There is precedent for former presidents joining forces for post-disaster fundraising. George HW Bush and Bill Clinton raised money together after the 2004 South Asia tsunami and Hurricane Katrina the next year. Clinton and George W Bush combined to seek donations after Haiti's 2011 earthquake.