Act 1 Scene 1 in William Shakespeare’s Macbeth is a very short scene that does a great job of setting the scene for the rest of the play by creating an atmosphere of deep foreboding.
The only characters are the three witches. The scene is described as “a desert place” with “thunder and lightning.”
The words the witches use contribute to the negative atmosphere. The second witch says:
When the battle's lost and won.
This implies that things are going to be confused and mixed up.
At the end of the scene, all the witches together say:
Fair is foul, and foul is fair:
Hover through the fog and filthy air.
Again, this emphasizes the idea that events are going to be unpredictable.
They also say that when they meet again, they will also meet with Macbeth. The fact that all of this negative foreshadowing includes Macbeth makes the audience realize that the main character is probably in for a lot of trouble.
Act 1, Scene 1, though very short, accomplishes quite a bit in terms of setting the mood. The mood is the emotional setting of a literary text. By introducing the play with these strange witches, Shakespeare establishes an eerie, otherworldy mood; it's a sign that things which seem impossible will be possible in this play.
Further, the Weird Sisters' speak primarily in rhyming couplets. This makes their speech seem chant-like, as though they are casting a spell. They are also the characters who first speak Macbeth's name, and this sets up a sense of foreboding, foreshadowing their danger to him.
Finally, they conclude the scene with the lines, "Fair is foul, and foul is fair; / Hover through the fog and filthy air" (1.1.12-13). The first of these lines is a paradox: how can fair be foul and vice versa? One possible solution to the paradox is that things that are actually fair will look foul, and things that are actually foul will seem fair. The content of this message is disturbing and off-putting: how will anyone know who to trust if a character who looks fair might actually be foul? In addition, the alliteration of the letter "f" sounds faintly snake-like, and sort of dirty, further adding to the sense of mystery and malice in this scene.
The opening scene establishes a very ominous, dark atmosphere that influences the whole play. it is set in 'a desert place', far from the trappings of civilization, and there is a storm raging.
The only characters that appear on this scene are the three witches, or 'weird sisters', and not ordinary human beings (whether of high social standing or otherwise). The very first scene gives us a sense of supernatural darkness. This helps to establish the feeling that what goes on in this play is not just confined to the human realm, that there are evil forces at work which threaten to overwhelm, to confuse: 'fair is foul, and foul is fair'. This short, alliterative chant by the witches memorably informs us that things are not necessarily what they seem, hinting at the overthrow of order, and painting a picture of unnatural happenings, which will involve the titular character, Macbeth (the witches say that they will shortly be meeting with him).
The whole play is drenched in this dark atmosphere which is evident right from the beginning. And Macbeth, who initially appears in a positive light as a dignified nobleman, mighty warrior and much-loved kinsman, a loyal server of his king, does indeed go on to overturn all these perceptions as he kills the king and arranges the murder of others in order to achieve his ambition (although he does suffer from a terribly guilty conscience). It is a moot point whether there is an actual supernatural force driving him down this dark path, or whether the evil springs from entirely within himself and is merely confirmed by the witches.