In terms of chords and melody, this is what falling in love feels like 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.
this is what falling in love feels like is written in the key of B 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 (B Major, E Major, and F♯ Major). See the B Major Cheat Sheet for popular chords, chord progressions, downloadable midi files and more!