In late 1977, while in rehearsal for their next album and just days before the band was set to enter the studio, Osbourne abruptly quit the band. Iommi called vocalist Dave Walker, a longtime friend of the band who had previously been a member of Fleetwood Mac and Savoy Brown, and informed him that Osbourne had left the band. Walker, who was at that time fronting a band called Mistress, flew to Birmingham from California in late 1977 to write material and rehearse with Black Sabbath. On 8 January 1978, Walker made his only live performance with Black Sabbath, on vocals, when they played an early version of the song "Junior's Eyes" on the BBC Television programme Look! Hear! Walker later recalled that, while in Birmingham, he had bumped into Osbourne in a pub and came to the conclusion that Osbourne was not fully committed to leaving Black Sabbath. Walker has said that he wrote a lot of lyrics during his brief time in the band, but none of them were ever used. Osbourne returned shortly thereafter.
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