Many genres of music have songs that are mostly comprised of a handful of chord sequences, or 'chord progressions'. For instance, you will hear the I - IV - V a

Many genres of music have songs that are mostly comprised of a handful of chord sequences, or 'chord progressions'. For instance, you will hear the I - IV - V all the time in western pop. An example of this (with a different chord progression): https://www.youtube.com/watch?v=oOlDewpCfZQ https://www.youtube.com/watch?v=oOlDewpCfZQ So unexpected harmonies are sequences that don;t fit in to these well-known, 'standard' progressions.