Survivor confirmed the news on Monday on its Facebook page.
Jamison’s booking manager Sally Irwin told TMZ, which broke the news, that a heart attack was the cause of death. The singer/songwriter was about to embark on a tour with Survivor starting Sept. 12 in Parker, Colo., according to the band’s website.
Survivor may be best known for “Rocky III” theme song “Eye of the Tiger.” Jamison joined the group after the dissolution of his band Cobra in 1984, two years after the hit single was released, and original Survivor vocalist Dave Bickler was forced to leave due to polyps on his vocal chords. Jamison provided vocals for the band’s “The Search is Over,” “Is This Love” and “The Moment of Truth” and “Burning Heart” from “The Karate Kid” and “Rocky IV,” respectively.
Jamison also co-wrote and sang on the “Baywatch” theme song “I’m Always Here.”
His “Eye of the Tiger” parody for a 2004 Starbucks commercial earned him an Emmy nomination.
Jamison previously left Survivor in 2006 to focus on a solo career, but returned in Nov. 2011. The Memphis-native did release a solo album titled “Never Too Late” in 2012.
He was set to band together with Bickler, Survivor guitarist Frankie Sullivan and bassist Bill Ozzello for the upcoming tour, hitting several spots in the U.S. and other countries including Germany, Sweden and England. It’s unclear if the tour will continue in the wake of his death.
Jamison had very recently played with Survivor on Aug. 30 for a show in Morgan Hill, Calif.