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.

The legendary rock star, Black Sabbath frontman and reality TV personality died on July 22 at 76. About two weeks prior, he played his final concert in his native Birmingham, England.

Following statements by Tony Iommi and Geezer Butler, Black Sabbath founding drummer Bill Ward has weighed in with his first posting since the death of Ozzy Osbourne.