In terms of chords and melody, Cosmic is significantly more complex than the typical song, having above average scores in Chord Complexity, Melodic Complexity, Chord-Melody Tension, Chord Progression Novelty and Chord-Bass Melody.
Cosmic is written in the key of A♭ Major. According to the Theorytab database, it is the 11st most popular key among Major keys and the 18th most popular among all keys. Major keys, along with minor keys, are a common choice for popular songs. The three most important chords, built off the 1st, 4th and 5th scale degrees are all major chords (A♭ Major, D♭ Major, and E♭ Major). See the A♭ Major Cheat Sheet for popular chords, chord progressions, downloadable midi files and more!