With enough flatpicking chops to rival the best in the business and an unvarnished voice to match, Virginia's Larry Keel remains one of the most intriguing characters in the modern bluegrass scene. He channels the eccentricities of John Hartford by spiking traditional conventions with new Americana weirdness; indeed, Keel has covered and collaborated with Hartford, though he favors fishing to piloting steamboats. Tonight, he steers the four-piece Natural Bridge through a night of loose jams; expect him to have a surprise up his sleeve. Acoustic Manner opens at 9 p.m. —Spencer Griffith