We already posted about one very noteworthy special guest, Fiona Apple, at Girlschool Festival, which happened at LA's Bootleg Theater over the weekend (2/2-2/4). The three-day festival, a benefit for girl positive charities (this year's beneficiary was WriteGirl) had a second unannounced special guest, Karen O of Yeah Yeah Yeahs, appear on Friday during Kristin Kontrol's set. Billed as Kristin Kontrol and The Kids, Kristin led a band of children and teenagers. She explained in an interview with Nasty Galaxy, "I’m nearly a fly on the wall. The kids have learned a set of covers; we shift around who sings what. A few even picked up a new instrument." Karen O joined the group for a version of Yeah Yeah Yeahs' "Date With the Night," which you can watch video clips of below.

The Kids' set also included announced guests Bethany Cosentino and Bobb Bruno of Best Coast. As Los Angeles Times points out, they changed lyrics in the song they performed, "When I'm With You," from "I hate sleeping alone" to "I hate playing alone." Watch video clips of their set below, as well.

Friday started off with a keynote from Carrie Brownstein, in conversation with poet Morgan Parker. Los Angeles Times reports that their talk touched on the #MeToo and #TimesUp movements:

There was a lot to get into, but the two kept their talk relatively optimistic and art-focused — and in 2018, consider this a welcome break from the daily shriek of American political life. They also admitted that movements such as #MeToo and #TimesUp can take an awful lot out of the people fighting for them as well.

"Real participation is vulnerable," Brownstein said, of the current waves of activism in the face of so many challenges. "To not still be figuring something out is a red flag."

"People ask me how it feels to be making people uncomfortable," Parker added. "Well, I feel uncomfortable."

Before she covered "You Don't Own Me" with Fiona on Saturday, Shirley Manson performed a few favorites from Garbage's discography, including "Only Happy When it Rains," "Bleed Like Me," "Cherry Lips," and "The Trick is to Keep Breathing," backed by string players and The Girlschool Choir, which was made up some of the weekend's performers. Watch videos of her set below too.