Help please. Interesting Progression


Stumbled on this track which has an interesting second chord in a four chord rotation.

Can anyone help with the progression/key?

I spotted Eb/B (with Bb in right hand)/C#/Ab which with suitable inversions sounds about right.



I - ♭VI7 - VII - IV (E♭ - C♭Maj7 - D♭ - A♭) in E♭ Mixolydian. At around 0:59 it becomes VII - VI7 - V - i - III7 - VII - iv6 in E♭ Minor; the four chords become i - VI7 - VII - iv until 2:25.

After that the progression returns to the mixolydian version once, then repeats VII - I - ♭VI7. At 3:03 the progression returns to the minor version.

Some sus2 or add9 chords may be present.

Wow! Many thanks for the prompt and comprehensive response. Should have know it’d be modal. Is this a common structure? It sounds a little atypical to me.

Thanks again!