In the wake of his death, Ozzy Osbourne’s Black Sabbath bandmate is shedding light on the quiet struggle behind the rock group’s final show. Tony Iommi, Black Sabbath guitarist and co-founder, told UK broadcaster ITV that Osbourne was “frustrated” during the band’s farewell concert on July 5.

On July 5, the Aquaman actor hosted the legendary rocker's final Black Sabbath concert in Osbourne's hometown of Birmingham, England. Four days before Osbourne's death at age 76 on Tuesday July 22, Momoa spoke with PEOPLE about the experience while doing press for his new Apple TV+ series Chief of War.

Ozzy Osbourne has died at age 76 more than two weeks after his final performance. The “Prince of Darkness” died “surrounded by love” on Tuesday, July 22, according to a statement posted by Osbourne’s family on social media.