Possible interpretation (spoilers)

Is it just me, or do the events in the film suggest that the entire thing takes place in Felisberto's head?

My theory goes roughly this- Felisberto actually is Adolfo, who witnessed some kind of traumatic event (maybe his fiance's death, maybe something else, more later). To cope with this trauma, he created the persona of Felisberto Fernandez, the piano tuner. The doctor and Assumpta are real people, who are trying to guide him out of his delusion through a series of process which Felisberto interprets as automata. At one point Felisberto says that his family have been piano tuners for 300 years, but that none of them were born. They were not born, because Felisberto is not a real person! Later, when Felisberto sees his reflection devoured by (I think it was the sixth?) automata, the doctor comments "You didn't think I could do that, did you". This is him breaking away a part of his delusion. Finally, tragically, as he is guided back towards the traumatic event (possibly violent, what else would the axeman automata represent?) Felisberto regresses and believes he has just arrived back at the doctor's villa (or, more likely, the insane asylum). At the beginning of the film it's explained to him that it is him in the fresco, and he mentions feeling like he'd done this all before- it's because he can never break through the barrier he's created to shield himself from whatever trauma he's hiding from.

I also had the impression that Assumpta might have been hi actual fiance, only much older now, because Felisberto has been trapped inside of his delusion for so long. At the end, when the doctor sets her free, she has finally given up on him and moved on with her life in the real world- the first time we see the sky in the film.

Anyway, just my thought on the initial viewing. Very good film by the way.