Many would argue that Motion Pool, the project’s only full-length, is Robert Hampson’s masterwork under the Main banner, but this collection of six 20-minute EPs, later gathered as a two-CD set, feels like his vision for the duo expressed in its purest possible form. The tracks are as much sound design as music, often built out of gently ticking patterns that explicitly abjure any rhythmic function, with pastoral hums layered around them and the occasional surprise (a saxophone doing non-saxophone-type things on the two parts of “Corona,” the only pieces here which really exhibit anything close to song form, thanks to a deep, dubby bass line and some heavily treated vocals). By the time you get to the end of the journey, the three-part “Neper,” conventional ideas of music have been almost entirely abandoned; you may think you’re listening to a half-obliterated radio broadcast of sounds from beyond the galaxy.