Olga (Elena Fokina) has reached a breaking point, and is unable to cope with the fact that nothing has been done about the disappearance of fellow dancer Patricia (Chloe Moretz). She cries and curses the instructors, calling them witches, and it’s a rebellious act that cannot be tolerated. Without her knowing, Susie (Dakota Johnson) is enchanted to essentially control Olga’s body, and during an intercut montage is shown to contort and kill her. The music is simple, all played on a piano, but the escalation is remarkable and has you leaving fingernail imprints in the armrest as you watch it play out.
Article source: https://www.cinemablend.com/news/2464103/the-10-best-movie-music-moments-of-2018