Macbeth (opera)
The witches are sitting round a cauldron in a dark cave. They sing, and then dance a ballet which was written for the 1865 version.  The music sounds like magic.  Macbeth enters and wants the witches to tell him his future.  They conjure up three apparitions for him. The first one tells him to beware of Macduff. The second tells him that he cannot be harmed by a man 'born of woman'. The third one says that he cannot be conquered till Birnam Wood marches against him.