Thanks to the nimble fingers and free-wheeling musical instincts of, respectively, noted session bassist Edgar Meyer and Nickel Creek/Punch Brothers fret whiz Chris Thile, stout double-bass and diminutive mandolin forge a union here that’s as rewarding as it is full of sly surprises. The album willfully blurs the distinctions between classical, bluegrass, folk and jazz with an organic, loose-limbed zest. “Ham and Cheese” invites listeners in, a sprightly workout that plays Thile’s fleet fingers off Meyer’s autumnal bowings with wit and charm, before the riff-chasing “The Farmer and the Duck” begins to show the truly adventurous spirit these two friends and gifted players inspire in each other. The frantic angularities of “Rabbit Cake” push both modal and genre boundaries, while “FRB” ("Forget" Ray Brown) also gives a playful wink at T. Monk’s herky tempos and elastic sense of rhythm. Yet their sense of adventure comes tempered with a graceful, introspective melodic melancholy on tracks like “Slow Song for a Dog” and the elegiac “Cassandra’s Waltz,” one that brings the duo’s often aggressive creativity gratifyingly full circle.