A most disturbing movie

I've just viewed The Pianist (La Pianiste) by Haneke. It's about a 40ish professor of music, Erika, played by Isabelle Huppert, who lives with her angry & invasive mother whilst teaching at the conservatorium in Vienna. Her behaviour toward her students is abusive and manipulative. She makes little, if any, positive feedback about their playing, instead belittling apparently talented players. A gifted young pianist is attracted to her, and attempts to establish a relationship with her. The ensuing interaction plays out Erika's mental sickness as shes swings between dominating behaviour and the desire to be dominated. What follows is destructive to all the major players.