5 Sabbath riffs you should know: TG delves into Tony Iommi's back catalogue to choose a few favourite riffs.
Killing Yourself To Live
Under The Sun
Tutor: Chris Bird
Videographer: Martin Holmes
Download Total Guitar issue 250 for the accompanying feature - available in the UK and, digitally, worldwide via Newsstand for iPad, iPhone & iPod touch and Zinio (http://www.zinio.com) from 20 January 2014.