Ozzy Osbourne, the frontman of heavy metal band Black Sabbath, has died at the age of 76 in the UK. He had been diagnosed with Parkinson's disease in 2019 and had recently performed at a farewell concert in Birmingham. Tributes have been paid by his bandmates, other musicians, and fans. Osbourne was known for his energetic and controversial live shows, as well as his appearances on reality TV shows.