Known mostly for his innovative guitar compositions in the ’90s that turned MBV squeals to liquid and foreshadowed the atmospheric electronic work of acts like Pole and Oval, Portuguese-born Rafael Toral has, over the years, moved toward a curatorial role amongst avant-garde experimenters. Recorded for his Space Program series, Space Elements, Vol. 1 finds Toral shaping tracks around a guest contributors’ chosen instrument; “I.I,” for instance, erects a moaning ambient passage behind cellist Rute Praça’s atonal wails. Recalling free-jazz structures, the record’s seven tracks investigate the space between sounds, exploring the role of silence in music. But it favors high concept over melody (or “songs,” even), and Space Elements is far more interesting than it is listenable.