Iommi is a Heavy Metal album by Black Sabbath guitarist Tony Iommi and myriad guest musicians and vocalists, including Skin of Skunk Anansie, Dave Grohl of Nirvana and the Foo Fighters, Billy Corgan of the Smashing Pumpkins, Serj Tankian of System of a Down, Billy Idol and Black Sabbath bandmate Ozzy Osbourne, to name a few. The album took nearly 5 years to make. All of the songs were written by Iommi, producer Bob Marlette and the respective vocalists of each track (except "Black Oblivion", which was written by only Iommi and Billy Corgan).