These [0] are examples of chord progressions. In other words, progression means nothing more than a series of chords. A "harmonically unexpected chord" would be

These [0] are examples of chord progressions. In other words, progression means nothing more than a series of chords. A "harmonically unexpected chord" would be if the chord progression was playing out and a chord you wouldn't normally hear was inserted. That's it. Musicians, especially those focused on classical music, are so used to the standard chords that it feels really weird to play a "wrong" chord progression. [0] https://www.youtube.com/watch?v=9YS3YvtY8-E https://www.youtube.com/watch?v=9YS3YvtY8-E