In terms of chords and melody, 2004 Breakup has complexity on par with the typical song, having near-average scores in Chord Complexity, Chord-Melody Tension and Chord-Bass Melody and below-average scores in Melodic Complexity and Chord Progression Novelty.
2004 Breakup has sections analyzed in the following keys: C♯ Minor, and A♭ Major. Click on the linked cheat sheets for popular chords, chord progressions, downloadable midi files and more!