Ozzy Osbourne has been remembered as a “pioneer,” a “fearless talent” and a “dear friend,” in an outpouring of tributes from fellow musicians and his former Black Sabbath bandmates following his death on Tuesday at the age of 76.

Born John Michael Osbourne, the English musician rose to fame as the so-called Prince of Darkness with his heavy metal band, Black Sabbath, which he co-founded in 1968. The band released popular hits like “Paranoid,” “Iron Man” and “War Pigs.”