

Passenger performing "Let Her Go" live in Bogotá, Colombia during his Runaway Tour. Rosenberg's vocals span from D4 to the high note of E5. The song is performed in the key of G major, played with a capo on the seventh fret of the guitar. Including acoustic guitar and vocals from Rosenberg, backing vocals, piano, drums, bass, and strings, the song is instrumentally diverse. The second half of the final chorus is performed a cappella. "Let Her Go" is driven by a chorus which is repeated five times throughout the song. The song's intro is inspired by the outro of the Red Hot Chili Peppers song " Slow Cheetah".

The verses give detailed scenes involving a heartbroken man dealing with his breakup.

The chorus describes situations in which one does not appreciate what he/she has until it is gone, and relates this to love. The lyrics of the song are poetic and melancholic, describing the regrets associated with ending a relationship.
