Music Director Designate Rafael Payare’s heady concerts with the San Diego Symphony last weekend marked the opening of the orchestra’s bravely titled “Hearing the Future” festival. In an interview at the Jacobs Music Center, Festival Curator Matthew Aucoin explained what the curious title means and how it came about. “When I was first talking to [San Diego Symphony C.E.O.] Martha Gilmer, I first thought we might simply present a lot of music by young composers, implying that they represent the future. But our culture already has too much of a youth obsession, and I thought we needed to take a…