How much energy can be generated in one matchup? We're about to find out as Green Day and System of a Down go head-to-head in this Round 2 pairing of the Mosh Pit Region to determine the Best Live Band.

On one side, you've got Green Day -- modern punk's premiere trio and Round 1 victors over Iggy and the Stooges. The band is just at home in a major arena or stadium as they are performing in the sweaty clubs where they began their career. And part of the fun of their sets is never knowing exactly what Billie Joe Armstrong and the boys are going to do. Will a fan come out of the audience to play? Will they play a medley of unexpected cover songs? Will some stage banter turn confrontational or hilarious? One thing you can expect is a show that will leave you truly rocked.

And speaking of truly rocked, System of a Down definitely know how to do that. The band bested Korn in a tight Round 1 matchup. With charismatic vocalist Serj Tankian leading the way with tongue-twisty lyrics smoothly delivered over a melange of frenetic and at times crushing hard rock sounds, a System of a Down show is something you truly need to experience. Even though it's been a decade since their last studio album and touring has been mixed in with side projects over the same period, when these four guys get onstage, it's as if they haven't missed a beat.

So which band will advance in this Best Live Band competition -- Green Day or System of a Down? You can vote once per hour through the deadline of Tuesday, July 21 at 10AM ET. So make your choice in the poll below and come back as often as you'd like to make sure your favorite live act advances.

See All the Brackets in the Best Live Band Tournament: