Hildur Guðnadóttir became only the fourth woman to win an Academy Award for a film score, and the first since 1997, as she walked away with honors for her “Joker” music Sunday night.

“To the girls, to the women, to the mothers, to the daughters, who hear the music bubbling within, please speak up. We need to hear your voices,” she said in accepting the award.

Iceland-born, Berlin-based Guðnadóttir represents a rare case of a composer being brought in before shooting to provide original music. She composed a theme for Joaquin Phoenix’s Joker character after reading the script, and the actor danced to the sound of her electro-acoustic cello on-set.

Backstage, Guðnadóttir said to write her music, she tries to picture what the character is going through. In the case of Phoenix’s “Joker,” he was “a man who was going through this excruciating journey,” she said. “I tried to imagine what was going on in his head.”

When asked whether she had noticed that she was getting a standing ovation — particularly from her fellow nominees — Guðnadóttir said: “It’s a wild moment. I heard my name, and I was thinking, ‘I can do this, I can do this.’ It floored me.” She added that during awards season, she had met her competition, and it’s been “really magical to get to know them.”

Guðnadóttir talked about how rare it is for a woman composer to be lauded in the film industry, and thinks her nomination (and now win) has brought attention to how bad the statistics are. “It has kind of poked a lot of people,” she said. She hopes the realization has made people think “this is a little bit silly, and we should be opening up the industry to more women.”

She said she had written most of the movie’s music before shooting for “Joker” started, and later learned that director Todd Phillips would play it on set. About Phoenix’s now famous dance on the top of the stairs, Guðnadóttir said, “It was so incredible to see that Joaquin had channeled exactly what I felt when I wrote it.”

When asked whether she might consider moving to Los Angeles, the answer was a polite no. “It’s not really my climate,” Guðnadóttir said. “It’s a little too sunny. It wouldn’t really suit my music to live here.”

The last women to win the score award were Anne Dudley, in 1997 for “The Full Monty,” and Rachel Portman, in 1996 for “Emma.” Both won the award for best original musical or comedy score, when there were still two different scores given every year, the other one being for drama score. The only woman to win a score award before that was Marilyn Bergman, who shared a “Yentl” win in 1983 with husband Alan Bergman and Michel Legrand, for song score, a category that was later phased out.

“Thank you to the Academy for welcoming me so warmly,” she said in her acceptance speech. “My fellow nominees, masters of the craft, it’s been such an honor to get to know you all.” Guðnadóttir added that “a film composter is only as creative as the director” and thanked Phillips for “listen(ing) to me the whole way — so attentive. I thank you for that so deeply.”

Guðnadóttir prevailed in the voting over four more veteran composers, three of whom already had Academy Awards. John Williams, who celebrated his 77th birthday the day before, was on his 52nd nomination, for the latest “Star Wars” film. Alexandre Desplat, nominated for “Little Women,” was a previous winner, as was Randy Newman, up for “Marriage Story,” although his two previous Oscar wins came in the song category. Among this year’s five nominees, only Thomas Newman, nominated for “1917,” lacks an Oscar now, after being up for it 15 times.