Ozzy Osbourne and Ronnie James Dio are two of heavy metal’s most iconic voices but with very different strengths. Ozzy’s vocals were raw haunting and often imperfect yet that unpolished wail became the sound of Black Sabbath’s dark heavy riffs. His voice carried a unique emotional weight that matched the doom of early metal. Ronnie James Dio came later with a voice that was powerful precise and almost operatic. His soaring delivery gave bands like Rainbow Black Sabbath and Dio a mythic epic qual