The lineup included his bandmates in the Allmans - guitarists Warren Haynes and Derek Trucks, who announced shortly after that show that they'd be leaving the band at year's end - as well as his peers (Jackson Browne, Dr. John), his son (Devon Allman) and his disciples from the jam-band world (Widespread Panic). It also included artists from the country music world (Trace Adkins, Martina McBride, Eric Church), plus one of his influences (Sam Moore from legendary '60s soul duo Sam & Dave). A live album and concert film from the event, called All My Friends will be out on May 6.

The show had many highlights, and one of them was Church's performance. The country superstar took on the lead track from 1972′s Eat A Peach, "Ain't Wastin' Time No More," as well as "Win, Lose or Draw," the title track from the band's 1975 LP.

"The great thing that Gregg Allman and the Allman Brothers and a lot of people from that era did best is they let the music be the music," Church said. "They didn't try to manufacture it, they let the creativity happen."

"He tore that up," Allman told Radio.com about Church's performance, during a phone conversation last week."But please print this: it's hard to say who did the best job of what. They were all so wonderful."