An Edmonton summer rock festival’s lineup is filling out. Organizers of this July’s Rockin’ Thunder music festival had announced Creed and Three Days Grace as headliners in December. Joining Three Days Grace at the Exhibition Lands Racetrack on Saturday, July 11, are The Glorious Sons, Bif Naked and Calling All Captains. Creed will play the next day along with Mammoth, Buckcherry and Paul Langlois of The Tragically Hip. The Watchmen are also slated to perform on an undisclosed date. Tickets for a Pit Pass, a Platinum Experience and general admission are on sale. Single-day prices start at $172.17 per ticket, two-day passes at $286.01 per. Chair rentals are also available. Last year’s Rockin’ Thunder fest, also held at the racetrack, featured Def Leppard, Weezer, Joan Jett and the Blackhearts, Stone Temple Pilots, Bret Michaels of Poison fame, Queensrÿche and The Trews.