Justin Dylan RenneyFor all our festival coverage, visit Bumbershoot.SeattleWeekly.com.Who: Say HiWhere: Broad Street StageWhen: 2:30 p.m.One part surf rock and two parts pop, Say Hi sounds like a Top 40-version of Grizzly Bear. There’s less doo-wop and little more emo, but solo artist Eric Elbogen pushes for the same kind of mellow harmonies with his bass player and back-up vocalist. Elbogen is known for having a rotating cast of musicians accompany him on tour, but he dropped hints that his new bass player is permanent addition–for now. “Say something while I tune,” he told Andy, the bassist, while tuning his guitar between songs.”Okay,” Andy said. “Why’d you change your band name?” (Say Hi was formerly called Say Hi to Your Mom, but Elbogen changed the name with the release of 2008’s The Wishes and The Glitch.)”You had to ask that?” Elbogen laughed. “Second gig with the band and you’re already fired.”