This coming week and weekend, Oct. 7–10, tens of thousands of hard rock and heavy metal fans descend on Discovery Park for what’s billed as the West Coast’s biggest rock festival. Aftershock boasts an epic lineup of dozens of bands on multiple stages over four days. Although the event has been sold out for its sixth year, some single-day tickets have opened up in this last week before the event. Quantities are extremely limited, but if you hurry, you might luck out! Among the headliners: Metallica, Rancid, Anthrax and The Original Misfits.