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.

“We’re heartbroken to hear about the passing of our brother in rock, Ozzy Osbourne. A voice that changed music forever. From Black Sabbath to his solo work, Ozzy redefined what it meant to be heavy. He did it all with heart, grit, and that wild spirit only he could bring.”

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.”