When Halsey took the stage at the Nobel Peace Prize Concert on Sunday (October 11) in Oslo, Norway, in a flowing black gown and bare feet, her most powerful accessory was a leather motorcycle jacket with the numbers "20:1" painted on the back. This was, as it turned out, Halsey's way of low-key calling out the entire ceremony.

"The number on this jacket represents the ratio of male-to-female recipients of the Nobel Prize, an award that recognizes great achievements in social, creative and scientific fields," Halsey told fans on Instagram after the show. "An award that this year finds itself belonging to not a single woman."

Since the Nobel Prize began in 1895, only 48 women have received the prestigious award. In total, 870 individuals have won over the decades. So yeah, Halsey's on to something here.

The jacket was a fitting look for "Castle," her latest single that's all about tackling the patriarchy: "I'm headed straight for the castle / They've got the kingdom locked up / And there's an old man sitting on the throne that's saying I should probably keep my pretty mouth shut."

Halsey ended her night by donating to foundations that support women's education so that someday the gender bias will even out. "I earnestly implore you to remind the women in your life that they are capable of greatness," she wrote. "The concert is over but there is much work to be done."