2AM revealed footage from their concert rehearsal on December 22nd through their official fancafe, and it's caused quite the sensation. Fans immediately noticed the new muscles the men were showing off, particularly maknae Jinwoon's. Being a ballad group, 2AM didn't have as many opportunities to show off their dance skills. But it looks like they're planning on bringing it to the concert, as the teaser revealed some intense choreography. The concert will be held on the 24th and 26th, and will tour throughout the nation.� Check out the video below! Source: Sports Chosun via Nate