The 10th annual (ähts): The Boston Arts Festival — which runs from Sept. 8 to 9 — will kick off with a free performance by Sharon Jones and the Dap-Kings on Sept. 7. This is the first time that the (ähts) festivities will start with a free Friday-night concert. According to Friday’s press release from Mayor Tom Menino’s office, soul and funk singer Jones (inset) and her band will play at Christopher Columbus Waterfront Park at 6 p.m. A note about Jones: She appeared in the Denzel Washington movie “The Great Debaters,” which was filmed at Harvard.