<p>The musical magicians who stole the spotlight by <a target='_blank' href='http://www.youtube.com/watch?v=d9NF2edxy-M&list=UU9PEibgWOqZ-1I1JdxRmr6g&index=19'>playing one big guitar</a> are back with their newest viral hit, an a capella cover of Taylor Swift's hit 'I Knew You Were Trouble.' <br> </p>
