DALLAS, TX – APRIL 25: Former U.S. presidents (L-R) Jimmy Carter, Bill Clinton, George H.W. Bush, George W. Bush and President Barack Obama pose at the opening of the George W. Bush Presidential Center April 25, 2013 in Dallas, Texas. (credit: Paul Morse/George W. Bush Presidential Center via Getty Images)

COLLEGE STATION, Texas (CBS11) – They are members of one of the world’s most exclusive clubs: The five former living presidents.

On Saturday night, Barack Obama, George W. Bush, Bill Clinton, George H.W. Bush and Jimmy Carter will make a rare, joint appearance at a concert benefitting hurricane relief efforts at Texas A&M University.

Security will be very tight for the event at Reed Arena.

The last time these five men came together was on May 1, 2013.

That’s when George W. Bush opened his presidential library at SMU in Dallas.

Security was even tighter back then because a sitting President was there.

That won’t be the case for the concert.

President Trump won’t be attending the event.

Robert Caltabiano is the former Special Agent In Charge of the U.S. Secret Office in Dallas and helped protect Presidents Obama, Bush 41 & 43, Clinton, Carter and Ronald Reagan.

He says protecting the former Presidents is more challenging today. “Protecting them has evolved now where years ago, you may not have put as many assets or things to go after protecting a former President. Why? Because most people didn’t want to threaten them.”

As a result, Caltabiano says there is now more planning and coordination between the Secret Service and others in law enforcement. “You’re going to have more people on the ground, more involvement between state and federal and local authorities, with EMS, with fire, with Homeland Security, with the FBI.”

Presidential historian Jeffrey Engel says the benefit concert is not only for a good cause, but sends a unifying message. “It’s really remarkable to have that many together and it really shows the nation whether you’re Republican or Democrat can come together for national causes.”

Engel is Director of the Center For Presidential at SMU and just wrote a new book about Bush 41’s Presidency: “When the World Seemed New: George H.W. Bush and The End of The Cold War.”

He says while a president’s term in office ends, the commitment to public service does not. “It really demonstrates at the highest levels what you have to be committed to first and foremost to become president is public service and what they care about most, all of them, is that the country succeeds.”

Those who are attending the concert Saturday night say they want to see the five Presidents together.

Tiffany Easter, a graduate student studying for a Masters Degree in Public Service Administration at the Bush School at Texas A&M says, “It’s a once in a lifetime opportunity. All five former living Presidents are going to be there. Why would you want to miss that?”

Gigi Shapiro says she and her husband are attending the concert because “It’s to benefit victims of Harvey. What a good, good thing. So we were excited about that and having all the presidents is a very rare occasion. So, everything about it excited us.”

Alabama, The Gatlin Brothers, and Lyle Lovett are among the musical acts performing Saturday night.

There are still tickets available, ranging from $30 to $600, for tomorrow night’s concert benefitting Hurricane relief efforts here in Texas, Florida, Puerto Rico and the Virgin Islands.