He tends to rely on progressions that feature mostly major chords, but arranged and voiced in a way that makes them sound minor (such as the beautiful I Remember: B - Dmaj7 - Gmaj7 - F# - Dmaj9 - ...

The chords are repetitive through the entire song, and you’ll only need 4 of them. Although it features 2 barre chords D6/9 and Dmaj9, they shouldn’t represent much of a hassle.