Olivia Colman on her Portishead cover with Phoebe Waller-Bridge: "The scariest thing I've ever done"

Olivia Colman is a force of nature in fare like The Favourite and Broadchurch, but the Oscar-winning actor melts before a microphone. As you can see in this behind-the-scenes clip for her new charity single, a cover of Portishead’s “Glory Box,” Colman is a maelstrom of nerves in the moments before recording. “I’d rather give birth again—with no drugs—than do this,” she cracks, calling it the “scariest thing I’ve ever done.”

Thankfully, she’s got a friend on hand. Her Fleabag co-star, Emmy-winning writer and actor Phoebe Waller-Bridge, soon swings by with a ukulele in tow (of course she plays ukulele). “It’s been a dream to support her musically,” Waller-Bridge says, noting that Colman is a “dark horse” at karaoke. She and her sister, Fleabag composer Isobel, both provide some backing instrumentation on the track.

They kill it, as you might expect, and you can hear the gorgeous cut in its full, ahem, glory below.

It’s collected on the charity compilation BBC Children in Need: Got It Covered, which aims to benefit disadvantaged children and young people throughout the U.K. The album, which is out now, also features covers from actors David Tennant and Helena Bonham-Carter.