"Million Years Ago" is a spare, lean song. The instrumentation is minimal, and Adele's voice is incredibly powerful. In an interview with Hattie Collins, she explains that it went on "at the last minute" and that it's "very stripped-back . . . just me on the guitar." The sparse musicality gives Adele's voice plenty of opportunity to do what it does best--wring ever tear and spare piece of emotion out of any listener who gets too close.