Is it a gig?” pondered writer Robert Macfarlane, introducing the second half of this quirky classical-meets-folk performance. As a duo, Stevens & Pound bill themselves as a “left-field folk” act. Their mashup of Pound’s folk background and Stevens’s classical training is all about high-energy, rhythmically driven virtuosity. There were some wonderful effects: terrifying, warmongering blasts of conch shell for Mars, bright flares of horn in Mercury, a whirlwind hoedown for Venus. Only the new movement, Earth, threaded with the tune of All Things Bright and Beautiful, briefly allowed more breathing space before yet another syncopated romp.