Dio is a heavy metal band led by vocalist Ronnie James Dio, who formed it in October 1982 after leaving Black Sabbath. In addition to Ronnie, Vivian Campbell played guitar; Jimmy Bain, bass; and Vinny Appice, drums.
In May 1983 they released their debut album Holy Diver, on which Ronnie sang and played keyboards. To avoid having the vocalist stuck behind a keyboard in concert, the band recruited keyboardist Claude Schnell.
Now a quintet, they released The Last in Line on July 2, 1984, followed by Sacred Heart on August 15, 1985. Several songs were recorded during the tour for that album; they were released along with the studio-recorded "Time To Burn" on the Intermission mini LP.
In 1986 Vivian Campbell left the band to join Whitesnake and was replaced by Craig Goldy. On July 21, 1987 their fourth album Dream Evil was released. After Dream Evil the entire Dio band was reconstructed introducing among other new musicians 19 year old guitarist Rowan Robertson. The new band released the album Lock up the Wolves. After this album Ronnie reunited with his former bandmates in Black Sabbath. The reunion was shortlived producing only one album. After this Ronnie James Dio reassembled the Dio band. At this time the guitarist Tracy G became a member of the band. During this era the band made the albums Strange Highways, Angry Machines and Inferno - Last in Live.
Goldy returned in 2000 for Dio's eighth studio album, Magica, but subsequently left before completion of Dio's ninth effort, Killing the Dragon, which was released in 2002 through Spitfire Records. Doug Aldrich was the guitarist on Killing The Dragon. Goldy returned once more to Dio in the summer of 2003. In 2004 Dio released their tenth studio album, Master of the Moon on September 7, 2004 in America through Sanctuary Records, and on August 30, 2004 in Europe through SPV Records. The album features multi-instrumentalist Jeff Pilson (ex- Dokken) on bass duties. Pilson had earlier played with Dio in the 1990s.