Pilobolus dance company members Otis Cook and Jennifer Macavinta perform the sensuous duet “Symbiosis.” Does it trace the birth of a human relationship, or the co-evolution of a pair of symbiotic species? That’s left for you to decide. Gorgeous, organic choreography blurs the boundaries between the two performers, who use the body’s own geometry to lift, move and combine. The music, recorded by the Kronos Quartet on Nonesuch Records, is a compilation of works: “God Music” from Black Angels by George Crumb, “Fratres” by Arvo Pärt, and “Morango … Almost a Tango” by Thomas Oboe Lee.