On June 16, 2010, at the Sonisphere Festival at Bemowo Airport in Warsaw, Poland, the "big four" of American thrash metal—Metallica, Slayer, Megadeth, and Anthrax—performed together for the first time. Megadeth was the second band to go on and played 12 songs.
Megadeth - The Big Four - Live from Sofia, Bulgaria's Main Cast