Quentin Tarantino Once Upon a Time in Hollywood is a simplified and bounded vision on the changes that came with the passing of a decade and its major events.
Tarantino recreates for the whole audience the well-known murder of Roman Polanski's wife, Sharon Tate. But the awarded filmmaker manages to go along with the Polanski and Tate story by setting another story in the same era, about a mediocre actor Rick Dalton (DiCaprio) and his stuntman Cliff Booth (Brad Pitt) and how they get involved somehow with the Manson Family who ends up performing the assassination of Sharon Tate and killing other two of her friends on the cold night of August 9 1969.
My point of view about this great film is simple as the movie it is for itself. I believe that Tarantino's idea was to portray the impact changing times in Hollywood, and how the passing from the 60's to the decade of the 70's entailed a big change in movies as much as it made to the society of Los Angeles at that time.
Quentin Tarantino has made it again. A great film, with an astonishing screenplay.