Unknown Mortal Orchestra’s Ruban Nielson is the latest in a long line of musical scavengers, racing to translate the sounds in his head by pulling from what’s already there. On the debut by Nielson’s erstwhile one-man band, Unknown Mortal Orchestra, that process involves building something new from reenacted hip-hop drum breaks, some doses of bad-trip psychedelia, and heavily processed slashes of garage-rock guitar. The project has since morphed into a Portland-based power trio, but on record, Nielson’s creation is by turns a crate-digging Voltron and a circuit-bent automaton. When all the pieces are working together—propelling through the lo-fi haze of “Ffunny Ffriends” or projecting the CB-radio soul of “How Can U Love Me”—it’s a quirky vision of a pop canon that never was; when the songs confuse a rut for a groove, their hypnotic qualities lapse into repetition. Nielson’s upper-register rasp occasionally recalls that of Paul McCartney, which seems appropriate—as a mercurial experiment in home recording, Unknown Mortal Orchestra lines up nicely with the ex-Beatle’s McCartney and McCartney II LPs. And like those two releases, Unknown Mortal Orchestra’s idiosyncrasies and straightforward melodies portend greater, untapped potential.