Explaining this chord progression I've noticed an interesting chord progression that I found in Stevie Wonder's song "Golden Lady" and a song by Janelle Monae called "Locked Inside", which was inspired by the former.

In the key of B, the progression would be Bmaj7, c#min7, d#min7, and then fmin7. What I'm wondering about is where this fmin7 comes from, and why it doesn't sound unnatural to the ear. Is it a constant structure thing?