The opposite of the 4-chord song (videos)

On its surface, “Never Gonna Let You Go” (produced by Sergio Mendes, written by Cynthia Weil and Barry Mann, and performed by a group of session musicians) sounds like a typical early 80s soft pop ballad. There’s a plinky synth, a duet (what was it with duets in the 80s?), and a guitar solo in the outro, which makes the song easy to write off as just another piece of fluff, but these videos show just how complex the song really is. The chord progressions look like a Calculus 3 math problem!