How does Shakespeare create dramatic tension for his audience from the beginning of Macbeth up until the end?

Shakespeare´s play ‘Macbeth´ is set in the heart of Scotland. The king at the time is king Duncun, a noble and honest king. He has two sons and many Thanes and noble men, one being Macbeth. Macbeth has fought his way up the ranks of the army to become one of Duncun´s most trusted Lords, but an encounter with three witches puts wickedness into the heart of an otherwise noble and loyal man.
In act 1, scene 1, a scene of three witches confronts us. This alone would have created mystery and fright to the audience, setting the scene of the play to come. ‘Macbeth´ was written in a period when there was a high interest in witchcraft and the supernatural. People were confused and scared by the supernatural, so the sight of three witches would have told the audience that the play would be full of evil and lies. This scene is a short opening to the play. It is long enough to awaken curiosity, but not to satisfy it. The mood of the play is set, although the action and the introduction o...