As the only member to have appeared in every incarnation of Black Sabbath, Tony Iommi hasn't been the most prolific solo artist. In fact, this keeper of the flame has only releasing two albums as a leader – 2000's 'Iommi' and 2005's 'Fused.' It's not Iommi's fault, however, as even his solo ideas tended to get absorbed into Black Sabbath. For instance, 1986's 'Seventh Star' was to be his proposed debut, before label executives insisted it be released under the Sabbath banner. Most of his work since retains a connection back to Black Sabbath. Glenn Hughes, the vocalist on 'Seventh Star,' later reunited with Iommi for 'Fused,' and was featured on a collection of sessions tracks titled '1996 DEP Sessions.' Iommi also collaborated with Black Sabbath contributors Ozzy Osbourne and Ian Gillan on the guest-packed 'Iommi' and 2012's 'WhoCares,' respectively. He made an appearance on the 2006 release 'Gillan's Inn,' too.