In terms of chords and melody, Sun has complexity on par with the typical song, having near-average scores in Chord Progression Novelty and below-average scores in Chord Complexity, Melodic Complexity, Chord-Melody Tension and Chord-Bass Melody.
Sun is written in the key of G♯ Dorian. According to the Theorytab database, it is the 11st most popular key among Dorian keys and the 48th most popular among all keys. The G♯ Dorian scale is similar to the G♯ Minor scale except that its 6th note is a half step higher (E♯). Chord progressions in Dorian have a characteristic sound due to the major quality of the chord built on the 4th scale degree. See the G♯ Dorian Cheat Sheet for popular chords, chord progressions, downloadable midi files and more!