"I went to a death metal show the other night... I was in the audience and I ran across the street and I had a beer in my hand and I was barefoot and I started headbanging with some strangers... and I just remember the bass player looked up and he was like, 'Holy f**k!'" Lady GaGa surprised a wannabe rock star by showing up unannounced at his band's gig at the South by Southwest festival in Austin, Texas earlier this week (beg10Mar14).