In terms of chords and melody, Sky Tower is more complex than the typical song, having above average scores in Melodic Complexity, Chord-Melody Tension, Chord Progression Novelty and Chord-Bass Melody.
Sky Tower is written in the key of B Dorian. According to the Theorytab database, it is the 7th most popular key among Dorian keys and the 37th most popular among all keys. The B Dorian scale is similar to the B Minor scale except that its 6th note is a half step higher (G♯). Chord progressions in Dorian have a characteristic sound due to the major quality of the chord built on the 4th scale degree. See the B Dorian Cheat Sheet for popular chords, chord progressions, downloadable midi files and more!