the "idée fixe" has now become a "vulgar dance tune", it is played on the e-flat clarinet. there are lots of effects, including ghostly "col legno" playing in the strings, the bubbling of the witches' cauldron played by the wind instruments. as the dance reaches a climax we hear the dies irae (day of judgement) melody together with the "ronde du sabbat" (sabbath round) which is a wild fugue.