In Macbeth, who dances and chants while making evil brew?

The three witches -- also known as the weird sisters -- danced and chanted while making evil brew. They appear in four scenes in the play.

They open the play (Act I, scene 1), when they predict that they will encounter Macbeth after the battle's done.

In Act I, scene 3, they give prophesies to Macbeth and Banquo that set the action of the play in motion. In Macbeth's case, they predict that he will become Thane of Cawdor (which happens almost immediately) and King (which happens only because his ambition leads him to commit murder). They also predict that Banquo will be lower ranked that Macbeth but happier, and that his sons will reach the throne.

In Act III, scene 5, Hecate (the goddess of witchcraft) tells the three witches that they shouldn't have acted without her, that Macbeth cares only for his own ends, and that they will prepare a spell to confuse and mislead Macbeth.

Finally, in Act IV, scene 1, they make their famous brew. One of the most famous lines from Shakespeare is found in this scene:

Double, double, toil and trouble;

Fire burn and cauldron bubble.

Then then proceed to conjure up three apparitions that fortell Macbeth's future -- confusingly, but in truth.