Good films always raise compelling questions, whether the format is fiction or documentary fact.

As somebody who had not heard any of this before, it became a curious phenomenon to sit and watch a film and slowly have the realities begin to click into place.

This is a must-see and one of the best documentaries - and films - of this year.

It is an exhilarating, distressing, funny and profound film, with one of the more memorable film scores in years,