At Saturday night’s 8 p.m. Live at the Rock free concert, when New Doubt takes on the looks and sounds of Southern California’s own Gwen Stefani and No Doubt, everyone is guaranteed a “Hella Good” time at Tortoise Rock Casino in Twentynine Palms. Now in its fifth season, Live at the Rock presents a new tribute on the outdoor stage every Saturday night. “New Doubt” covers the breadth of No Doubt’s sound from ska punk, reggae fusion, punk rock, new wave, and alternative rock.