Daily Piano Improv: 2021-10-10 Edition

The chord progression is ii-V-I-IV in the key of Eb major, so it goes Fm-Bb-Eb-Ab. This happens to be the same as in A-ha's hit "Take On Me", though that song is in A major.
The turnaround chord at 0:12 and 0:24 is the sixth scale degree which is the "relative minor" of the major key we're in (vi or Cm in Eb). However, at 0:12 I played it as a C major chord which has a characteristic flavor since its major third is outside of the key ("non-diatonic"). It functions as the dominant of the ii chord ("supertonic") which creates harmonic tension that pushes the music forward and allows me to avoid getting getting stuck on the I chord.