The morning after the Women’s March on Washington Saturday, members of the GW Sirens woke up to find that a video of them performing a song called “Quiet” had gotten more than 5,000 retweets.

Now, the group is headed to New York to perform on “Full Frontal with Samantha Bee” Wednesday night, and the video has been viewed 21 million times on Facebook and has been retweeted 70,000 times, including by stars like Emma Watson and Hayley Williams.

Despite their new-found fame, Juliette Geller, the publicist for the GW Sirens, said the group’s members are most excited that people found meaning in the song.

“When we first agreed to be a part of the project we had no idea it was going to take off like it did,” Geller said. “Then on the day of the march, we saw how many people showed up and watched us and realized wow this is a really big thing.”

Connie Lim, whose stage name is MILCK, reached out to the group via Facebook during winter break, asking them to perform “Quiet” at the Women’s March, Geller said.

Lim was “galvanized” by the election of U.S. President Donald Trump to write the song, which discusses strength and the importance of speaking out on issues she’s struggled with, like domestic violence and eating disorders, Geller said.

Lim sang a cappella in college and told the group she felt strongly about a cappella’s ability to “convey a message.” Although the song was originally created to be released as a single, she preferred a women’s a capella group premier it at the march.

It wasn’t until Thursday, just two days before the march, that the GW Sirens got together in person to rehearse with Lim and Capital Blend, an adult all-female a cappella group that joined them for the performance, Geller said. 

At the march, there was a call and response portion of the song in which members sang, “They’ll be someone who understands” and the rest of the group responded with, “Let it out, let it out, let it out now.” Geller said marchers connected most with that element of the performance. 

“Every single time I got to that part of the song I’d make eye contact with someone standing around watching,” she said. “I felt like there was this understanding, like clearly you’re the one who understands so let’s both let it out.”

Haley Amdur, the GW Sirens’ co-director of music, said each of the 10 to 15 times the group performed that morning, they were surrounded by bystanders with tear-filled eyes holding up their phones to record videos.

Amdur said seeing the intense reactions the singing evoked made the performance “powerful.” She and Geller both said they didn’t feel the full intensity and emotion of the song until the day of the march, when they performed it in front of other people for the first time.

“Anyone who chooses to spend their time singing finds some meaning in music and it was a really powerful way to get involved,” Amdur said.

Lim is planning to release the sheet music for “Quiet” on her website so choirs around the world can perform the song and join the #ICantKeepQuiet movement. She is also planning to sell a version of the song performed by her, the GW Sirens and Capital Blend, and all proceeds will go back to the Women’s March organization, Geller said. 

“The song is meant to uplift people,” Amdur said. “That’s what it did at the march and that’s what it can continue to do.”