In traditional mountain music circles, fiddle and mandolin virtuoso Sam Bush is rightly a legend, but he’s far from a traditionalist. It’s hard to believe now, but when Bush formed New Grass Revival in 1972, the combo’s seamless mix of bluegrass, rock, jazz and gospel was seen as a heresy on the order of Bob Dylan going electric at the Newport Jazz Festival. If that made Bush a “Judas,” he clearly didn’t care, pushing the Newgrass hybrid he invented further afield with his all-star bluegrass super group Strength in Numbers and as a sideman with Emmylou Harris, Lyle Lovett and others. Bush’s distinctive rhythmic “chopping” style on the mandolin was inspired by Bob Marley’s percussive rhythm guitar with the Wailers, and the reggae infusion into Newgrass reportedly pissed off Bush’s idol, bluegrass elder statesman Bill Monroe. Yet Bush says that purism is an illusion, pointing out that Monroe invented bluegrass in the 1930s as a hard-driving hybrid of Appalachian string music and blues. A three-time Grammy winner, Bush is also a two-time cancer survivor, so it’s doubly fitting that this treasured performer is the tent pole for a fest committed to raising funds and awareness for cancer organizations.