Kids and dogs. Boomers with ponytails. An unofficial Harley-Davidson convention. An estimated 1,000 harmonica lovers jammed the grassy amphitheater at Harry Griffen Park north of Grossmont High School for the 12th annual Spring Harp Fest—featuring a dozen acts and dancing in the aisles from noon to 7 p.m. Saturday. Budd Willis—an organizer and an MC along with John Frazer and Robb Bower—said the musicians were all volunteers. Sales of various items—including CDs, T-shirts and barbecued hamburgers—brought donations to Blues in the Schools, a program that gives presentations and hands out harmonicas—nearly 4,000 to date, organizers say.