When St. Jude Children’s Research Hospital came calling, Stanley Pierce didn’t hesitate. His son, Craig, had died from leukemia years before at age 10 after receiving treatment from the hospital known for its cancer research and for never sending a bill to families of patients it treats. The hospital asked if he’d be interested in playing host to a fundraiser. He said he’d “give it a shot,” and 20 years later, that fundraiser has turned into a free gospel singing benefit concert that has raised $480,000. This year’s concert is set for 6 p.m. Saturday, Aug. 4 at Hopewell Baptist Church in Gainesville.