In terms of chords and melody, Duet - OMORI OST is more complex than the typical song, having above average scores in Chord Complexity, Melodic Complexity, Chord-Melody Tension and Chord Progression Novelty.
Duet - OMORI OST is written in the key of C Major. According to the Theorytab database, it is the most common key in all of popular music. See the C Major Cheat Sheet for popular chords, chord progressions, downloadable midi files and more!