The second annual Monster Energy’s Aftershock Festival has expanded to a full weekend in 2013. The biggest weekend in rock to ever hit the capital of California will take place September 14th and 15th at Discovery Park near downtown Sacramento, CA.   Northern California's biggest summer rock ‘n’ roll festival will feature two main stages, with rare area headlining appearances from AVENGED SEVENFOLD and KORN, as well as a special additional headliner to be announced o...