In terms of chords and melody, The Firework is more complex than the typical song, having above average scores in Melodic Complexity, Chord-Melody Tension, Chord Progression Novelty and Chord-Bass Melody.
The Firework has sections analyzed in the following keys: A Dorian, and G Major. Click on the linked cheat sheets for popular chords, chord progressions, downloadable midi files and more!