ATLANTA (AP) -- When Col. Bruce Hampton slowly fell to his knees during the finale of his star-studded birthday concert, fans and musicians alike thought it was another one of his quirky performance acts.
Fourteen-year-old guitar phenom Brandon "Taz" Niederauer tore into a blistering solo as the 70-year-old man lay motionless at his feet, his arm draped over a speaker.
For several more minutes, dozens of musicians — including John Popper of Blues Traveler, Warren Haynes of The Allman Brothers Band and John Bell of Widespread Panic — jammed away to one of Hampton's favorite songs "Turn On Your Love Light." The fans danced and the musicians smiled as they waited for him to get up.
But Col. Bruce never did.
The eccentric guitarist and singer known as the forefather of the jam band scene died after collapsing Monday night at the end of the show billed by Atlanta's Fox Theatre as "Hampton 70: A Celebration of Col. Bruce Hampton." He had turned 70 a day earlier.
Drummer Jeff Sipe said Hampton made eye contact with him and grinned moments before he went down.
"I think he was smiling goodbye," Sipe said. He noted that Hampton had a heart attack in 2006 and was taking numerous medications while keeping up a rigorous touring schedule. A nurse told him that even if the musicians had responded immediately, he would not have been revived.
Hampton founded several bands, including the Hampton Grease Band and the Aquarium Rescue Unit, and had a knack for surrounding himself with talented musicians, including Derek Trucks of the Tedeschi Trucks Band and Jimmy Herring of Widespread Panic. He was described as a father figure, a spiritual guru and a crazy uncle by those who knew him.
While wealth and fame eluded him, he was widely acknowledged as an influence on other leading musicians. Keyboardist Chuck Leavell of the Rolling Stones, guitarist Peter Buck of R.E.M and drummer Jon Fishman of Phish were among the dozens of performers who honored him on Monday night.
Hampton was also an actor and played the role of a songwriting band manager in Billy Bob Thornton's 1996 film "Sling Blade."
Born Gustav Berglund III in Knoxville, Tennessee, he changed his name to Col. Bruce Hampton as an adult and started his career with Frank Zappa & the Mothers of Invention, appearing on "We're Only in It for the Money" in 1967 and "Lumpy Gravy" in 1968, according to Variety .
The Hampton Grease Band became known for its over-the-top, impromptu performances at Piedmont Park in Atlanta, opening the door for other counterculture acts such as The Allman Brothers Band to play in the vast urban green space.
In the 1990s, Hampton helped shape the H.O.R.D.E. tours with Popper and was later the subject of a documentary, "Basically Frightened: The Musical Madness of Colonel Bruce Hampton."
"Ever since I was a kid, I've been doing theater and just been a rabble-rouser," Hampton told Relix magazine in 2015. "I played basketball while I had a yellow coat on — not to attract attention, but just for the element of weirdness — and they threw me out of the league. I've always liked theatrics."
During the "Love Light" encore, Hampton beamed as he belted out the first part of the tune with his bluesy growl.
After he fell to his knees and people began to realize it was no stunt, the band abruptly ended the song and a hush fell over the crowd. Stunned fans looked at one another and asked, "What just happened?"
"We're going to take care of business backstage here," Sipe said. "Thank you so much. We love you so much. Thanks for honoring Bruce Hampton on his 70th."
As paramedics loaded Hampton into an ambulance, fans shouted "Brrruuuccccee" as they had done throughout the night.
"Thank you Colonel Bruce for everything you have taught me and the love you gave me over the past four years. And I thank all of the musicians and friends who are helping me through this. The Colonel lives thru all of us. RIP," Niederauer said in a statement.
Longtime Atlanta musicians such as Michelle Malone took to social media Tuesday, pouring out their admiration for the man they say encouraged and inspired them. "I will miss your wry sense of humor, your big weird brain, your great big kind heart, and your genius and endearing approach to music," Malone wrote.
The Tedeschi Trucks Band said in a statement that Hampton was truly surrounded by loving friends and family.
"It was a dramatic and poetic ending to the life of a man whose entire way of living was an art form, but cannot mitigate the sadness of all who loved him. He will be missed and always remembered."
Candles, flowers, a pair of drum sticks and other mementoes were part of a growing memorial at the entrance to the Fox Theatre on Tuesday.
Hampton showed no sign anything was amiss before his collapse. He appeared on stage early in the four-hour night, conducting and singing with a band. Later, he played and sang several tunes, including "I'm So Glad" as well as "Fixin' to Die," a song he had performed many times before. This time, though, the lyrics turned out to be prophetic:
Feeling funny in my mind, Lord
I believe I'm fixing to die
Well, I don't mind dying
But I hate to leave my children crying