In terms of chords and melody, One Night Only (Disco Version) is more complex than the typical song, having above average scores in Chord Complexity, Melodic Complexity, Chord Progression Novelty and Chord-Bass Melody.
One Night Only (Disco Version) is written in the key of B♭ Minor. According to the Theorytab database, it is the 11st most popular key among Minor keys and the 23rd 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!