A bluegrass band at their core, the Steep Canyon Rangers effortlessly walk the line between festival favorite and sophisticated string orchestra. They’re as danceable as the most progressive, party-oriented string band, and equally comfortable translating their songs for accompaniment by a full symphony. Their beautifully haunting penchant for yearning high harmonies, rollicking banjo-driven duets, serious chops, and good-natured fun earned them a Grammy for Best Bluegrass in 2013, drew enlistment from celebrated comedian / banjoist Steve Martin as a backing band, and collaborations with esteemed singer-songwriter Edie Brickell. Fifteen years and nine studio albums since forming in Chapel Hill, North Carolina the sextet have become world-class musicians just as at home at Carnegie Hall as they are knee-deep in a mountain brook, fly rod in hand. The Steep Canyon Rangers are Woody Platt (guitar), Graham Sharp (banjo), Charles R. Humphrey III (bass), Mike Guggino (mandolin), Nicky Sanders (fiddle) and Mike Ashworth (box kit). 8:00 p.m. Early Bird through 9/15: $35. Regular: $40