It's October ... or Rocktober as some hard rocking music fans have taken to calling it in recent years ... and we here at Loudwire are celebrating Rocktober with a new tournament in which we pick some of the biggest hard rock hits of the 21st Century and let the songs battle it out to see who comes out on top. Let's face it, it's been a veritable cornucopia of hard rocking songs that have commanded our attention over the last 16 years and there are some real heavyweight contenders for the title.

This tournament will include acts who were well established long before we all became anxious about the Y2K bug and have managed to survive and thrive well past that. But there are also a wealth of acts who have made their impact on the scene well after the start of the 21st Century and have helped usher in a new generation of hit songs commanding our airwaves as well. And just because it's "hard rock hits" doesn't mean that you won't find some heavier songs in this competition. Much like on radio, you'll find acts like Slipknot, Tool, Avenged Sevenfold and System of a Down competing for your votes of attention right alongside Red Hot Chili Peppers, Green Day, Foo Fighters and Linkin Park.

So, without further adieu, let's get down to it and see which song the Loudwire readers will vote as the Best Hard Rock Hit of the 21st Century. Voting is currently underway in Round 1 and for each matchup you can vote once per hour through the deadline of Monday, Oct. 17 at 10AM ET. Keep coming back and voting to ensure your favorites advance to the second round. Let the voting begin by clicking on the red button below to take you to the first pairing.