In terms of chords and melody, Grinning Mouths has complexity on par with the typical song, having near-average scores in Chord Complexity, Chord-Melody Tension and Chord Progression Novelty and below-average scores in Melodic Complexity and Chord-Bass Melody.
Grinning Mouths is written in the key of B Minor. According to the Theorytab database, it is the 6th most popular key among Minor keys and the 14th most popular among all keys. Minor keys, along with major keys, are a common choice for popular music. The three most important chords, built off the 1st, 4th and 5th scale degrees are all minor chords (B minor, E minor, and F♯ minor). See the B Minor Cheat Sheet for popular chords, chord progressions, downloadable midi files and more!