Despite the prosaic title, there’s nothing ordinary about this collection of curios and offcuts. In an alternate universe, “The Arrangement” could have been a lullaby-like centerpiece of 2008’s Teen Dream rather than a track sidelined because it didn’t quite fit the album’s cohesive mood. From 2005’s “Rain in Numbers”—a drunk, disconcerting cousin of Coldplay’s “Clocks”—to the lush, hymnal “Chariot” from 2015’s Depression Cherry/Thank Your Lucky Stars sessions, everything here carries the duo’s distinct skill for sneaking gripping melodies into darkened dream pop.