WARNING: Spoilers ahead for Midsommar.
Ari Aster’s Midsommar is partially based on a real life festival, but the customs don’t involve the same violence and pagan cult activities on show in the horror movie. The midsummer festival celebrates the beginning of summer, and takes place between June 19 and June 25. Various countries from all over the world organize midsummer events; Sweden's Midsummer's Eve, a Friday, is a national holiday. With Midsommar, Aster combines ancient folklore with these basic midsummer traditions (which were, once upon a time, associated with the birth of John the Baptist).
Midsommar stars Florence Pugh as Dani, a college student who makes a fateful trip to a Swedish commune, the home of her boyfriend’s college friend, Pelle (Vilhelm Blomgren). Upon arriving in Hårga, Dani learns that midsummer events involve the ritualistic suicide of locals who reach the age of 72, the end of a seasonal life cycle. One by one, Dani’s travel companions disappear, and she ultimately discovers her boyfriend having sex with a young local girl, the result of a carefully planned spell. In Midsommar’s final act, Dani is crowned the “May Queen” after winning a maypole dancing content, and the film ends with a fiery ritualistic sacrifice. The commune members collectively share feelings of joy and grief, allowing for Dani to feel right at home.
In Midsommar, the focal celebration is scary, bloody, and partially authentic. The titular festival supposedly takes place every 90 years, at least in the Hårga commune. That's part of the appeal for the main American characters; they can travel while learning about Pelle’s heritage and customs. Both Christian (Jack Reynor) and Josh (William Jackson Harper) use the opportunity to research for their respective thesis essays. In reality, however, the Summer Solstice event is celebrated annually in Sweden. For dramatic purposes, Aster takes a more specific approach with his narrative in order to make the communal traditions confuse the American travelers. While speaking with Rotten Tomatoes, Aster stated, “I was pulling from a lot of different spiritual movements that have nothing to do, in many cases, with even Sweden, but there are hundreds of things kind of woven together here."
Despite Midsommar’s contrived festival premise, the primary setting is indeed a real place. Aster chose Hårga because of its association with a real Swedish legend known as Hårgalåten: the devil arrives in Hårga, disguised as a fiddler, and tricks the young locals into dancing themselves to death. Midsommar incorporates “The Hårga Song” into the storyline, with Dani participating in a Hårgalåten-inspired dancing competition and becomes the new May Queen.
Aesthetically, Midsommar also stays true to real-life customs. Maypoles are traditionally staged to bring good fortune and health to the locals, specifically in terms of farming and peace of mind. Aster includes these concepts in Midsommar. In addition, Swedish midsummer customs involve the use of flowers for decoration, which is especially prevalent throughout Aster's Midsommar, most notably in the final act when Dani, the May Queen, is entirely overtaken by flowers (except for her face). In real life, flower crowns are reportedly “the hottest festival accessory.”
Finally, there’s even some truth to Midsommar’s love spell. In the movie, a young girl (Isabelle Grill as Maja) strategically places an item under Christian’s bed and hides pubic hair in his food. Real-life Scandinavian customs involve single women placing seven flowers under their pillow on midsummer’s eve, hoping to see their future husband in a dream. As a whole, Midsommar is essentially an extended fever dream, a breakup story that blends midsummer facts with cultural folklore.