How does Hitchcock create fear and tension through the structure of the story line in Psycho?

In this film Hitchcock does not use the traditional Hollywood equilibrium, disruption, solution pattern, as the main character is killed of 30 minutes into the film. It starts off traditionally with equilibrium, but there is no solution to the disruptions that occur. The first half of the film is very uneventful; it is all build up to the events that take place in the second half of the film. The music has a strong role in …

…is played when for example she is swapping her car; which is not a key moment in the film. The cause and effect theory that is so common in Hollywood films does not always apply in this film; that creates tension. For example: the main character decides to take the money back to its rightful owner, so she is murdered brutally in the shower. It is not logical and the viewers are not expecting it.