Stringed instruments have long been used to make people feel edgy.
Think of a double bass rasping “duh-nuh, duh-nuh” as Jaws approaches, or the screeching violins of Psycho as terror strikes.
There's something visceral about their sound, which can make your hair stand on end during a horrifying film sequence.
In Joker, the cello conveys the inner turmoil of Joaquin Phoenix's character Arthur Fleck, as he contorts into a murderous clown.
The film's soundtrack is the work of Icelandic composer and cellist Hildur Gudnadottir – the only woman nominated for best score at this year's Oscars.
Anyone who's seen the film will know the music plays an integral part.
“Joker is the story of basically one person, so it felt fitting that one instrument was leading the way into his head, leading us forward,” she tells BBC News.
Of all the instruments at her disposal, she chose the cello. “It's my instrument, so it was convenient as I played it on the soundtrack,” she says.
Hildur was lured into working on…