The centerpiece for the fourth annual HSL Properties Tucson Jazz Festival is the Downtown Jazz Fiesta, a daylong celebration of jazz features two outdoor stages on Fifth Avenue and a half dozen indoor venues, primarily on Congress Street. It’s free and sponsored by Rio Nuevo. We need volunteers for two hour shifts from 9 a.m. until 9 p.m. The sign-ups for the shifts will be later. Sign up now to be included in our emails.