Fennesz has one of the most recognizable signatures in electronic music, and it extends to his collaborative work. He applies a corrosive touch to Oneohtrix Point Never and Antony's “Returnal,” and his work with Ryuichi Sakamoto is a tug-of-war between lyrical melodicism and moody abstraction. In contrast, “Christian's Guitar Piece,” with Sparklehorse, is a rare chance to hear him unplugged.