Below, check out a fan-filmed clip of guitarists Marty Friedman and Gus G performing Black Sabbath's "Symptom of the Universe" May 1 at Klubi in Tampere, Finland, during their joint Guitar Universe 2014 tour.
"Symptom of the Universe," which originally appeared on Black Sabbath's 1975 album, Sabotage, has been covered by several artists over the years, including Sepultura, Helmet and the Melvins.
Be sure to check out Gus and Marty's impromptu version and let us know what you think in the comments below or on Facebook!
