Kelly Osbourne, the famous daughter of rocker Ozzy Osbourne, is speaking out after his death.

Kelly, 40, posted an Instagram story with a black screen and a broken heart emoji, accompanied by the text "I feel unhappy I am so sad. I lost the best friend I ever had."

The caption references the opening line to Black Sabbath's 1972 ballad "Changes." Osbourne, who died Tuesday, July 22, at 76, was the band's longtime vocalist. "Changes," off of Black Sabbath's 1972 album "Vol. 4," is one of the more sentimental songs among the group's heavy metal anthems.

In 2003, Osbourne and Kelly released a duet of the track rewritten to match their own story. The tender father-daughter remake served as a microcosm for the rocker's contradictions: a harsh, heavy metal shredder onstage, and a family man behind the scenes.

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