A music festival is bringing more than 200 acts — including Steve Earle, Los Lobos, Lake Street Dive and the Dirty Dozen Brass Band — to St. Augustine next month. And it’s all free. The Sing Out Loud Festival will be held over three weekends in September at the St. Augustine Amphitheatre and more than a dozen other venues. It’s being billed as the largest free music festival ever held in North Florida. Concerts will be held Sept. 8-10, Sept. 15-17 and Sept. 22-24.