In terms of chords and melody, Tomodachi Collection - Map - Day 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.
Tomodachi Collection - Map - Day is written in the key of D Major. According to the Theorytab database, it is the 2nd most popular key among Major keys and the 2nd 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 (D Major, G Major, and A Major). See the D Major Cheat Sheet for popular chords, chord progressions, downloadable midi files and more!