Mezzotint slots snugly into Kranky’s mold of meticulously chiseled ambient acts (Loscil, Chihei Hatakeyama, Pan American). Birmingham’s Chris Herbert defines himself as a non-musician, and his tweaking of found sounds and field recordings reveals an intuitive grasp of forlorn moods and evocative, gradually evolving textures. The poignancy of a distant airplane-engine drone is a common motif in much beatless music, and Herbert employs the convention well. Within his subtly oscillating tone collages, a gentle struggle between tranquility and turbulence plays out. The result is like being submerged in a sensory deprivation tank while someone introduces nettles into it.