I LOVE THIS! During a tour stop in Helsinki, Finland, the boys of Avenged Sevenfold decided to stop by the local Hard Rock Cafe for a few drinks. After knocking back a few too many, they got the liquid courage to take over the empty stage, grab some instruments laying around and perform "Nightmare." 

 The band wrote in the description of the video: "After arriving in Helsinki yesterday we decided to head to the local Hard Rock and grace the customers with some sweet tunes. Unfortunately, as the patrons fled for the exits we were cut off after only half of "Nightmare" was played."