There were nearly 300 feature films on the schedule at the Toronto Film Festival this year, but that didn’t stop Fox from making a big splash with a film that wasn’t even screened in its entirety at TIFF. Last weekend, Hidden Figures came to the Canadian city to show off 20 minutes of footage, followed by an open air concert by Pharrell Williams, a stone’s throw from the Lightbox.

The film tells the extraordinary story of Katherine Johnson, Dorothy Vaughn and Mary Jackson, three exceptionally talented African American women “computers” at NASA in the 1960s. They spent their days calculating the trajectories that would put John Glenn into orbit and send Neil Armstrong and Buzz Aldrin to the moon, all the while fighting the injustice of Virginia’s segregation laws. The film stars Octavia Spencer, Taraji P. Henson and Janelle Monáe. Pharrell Williams provides a number of original songs for the movie, which is directed by St. Vincent‘s Theodore Melfi.

“I didn’t know [the story] until I got the script,” Taraji P. Henson told me. “And I went to an historically black university, where Ron McNair – who died in the [Space Shuttle] launch to space – [had attended]. I actually studied electrical engineering. I failed, but I was there. And this man has a building named after him. If it wasn’t for Katherine Johnson, there would have been no Ron. But hey, who am I? Never heard of her. I was annoyed. I was mad. And this became my passion project. I was like, ‘I have to do this movie.'”

“I think there will be some people who think that this is some sort of conjecture,” Spencer said. “I thought it was fiction. But it’s an embarrassment that these women were omitted from the annals of history. I’m excited because the world will finally know these names. They will no longer be obscure.”

Pharrell Williams’ barnstorming concert could be heard all across the main festival drag. He summed up his interest simply: “Here are the variables: three African American women, math, science, NASA. How do I not do everything in my body to be a part of this project?”

Check out a video of the concert below, and more from our interview above.