"The Handmaid's Tale" star shows off her acting skills in the promo as she mourns the end of a same-sex romance only to realise at the last minute she still loves her girlfriend, played by Nicole Disson.
Carlile, who last week picked up six Grammy nods, admits she only wanted Moss for the lead in her new video after meeting the actress backstage during a TV show taping.
"When I thought about making a video for 'Party of One', I couldn't stop picturing Elisabeth's face," she says in a statement. "I believe she is the absolute best actor out there right now. No one has ever impacted me so much without saying a word. I never even asked anyone else."
And Elisabeth was happy to sign on, adding, "The main reason I wanted to be involved in this music video was because of this incredible song.
"I had accosted Brandi when we were both on Ellen ("The Ellen DeGeneres Show") because I had been obsessively listening to her cover of Bryan Adams' "Heaven" to help me prepare for a cover I had to do of it (song) for the movie "Her Smell".
"When she sent me this song and shortly afterwards had asked me to be involved in the creation of the video, I said yes immediately because I fell so head over heels in love with the track. It's one of those most beautiful musical pieces I've ever heard, right down to the string arrangement at the end."
The video was an all-female affair -it was directed by Berenice Eveno and produced by Diane Pellegrino and Kate Siegel.