Legendary Bay Area thrashers Megadeth announced Thursday that it will perform its classic 1992 album "Countdown to Extinction" in its entirety at a September 7th show in Santiago, Chile.  "Countdown" was Megadeth's first album to be certified double-platinum and contains several songs that are still live favorites for the band including "Sweating Bullets" and "Symphony of Destruction," which can be heard in the YouTube clip below.