CMAT chanted "Free Palestine" and waded into the Pyramid Stage crowd, who were dancing in the midday heat, during her Glastonbury Festival set on Friday.
CMAT, real name Ciara Mary-Alice Thompson, played songs from her back catalogue as well as new singles, including Take a Sexy Picture of Me, from her forthcoming third studio album, Euro-Country.
Plenty of festivalgoers could be seen doing the viral dance to the song, which has taken social media by storm in recent months.
Kicking off her set with Have Fun!, CMAT, who wore an all-purple ensemble with white boots, sang while lying flat on the floor before getting to her feet and shouting: "Glasto!"
CMAT, who blends pop and rock with folk and country influences, performed from her back catalogue, receiving rapturous applause while singing hits including I Don't Really Care for You.
The singer also encouraged fans to dance along to the "Dunboyne, County Meath two-step" while singing I Wanna Be a Cowboy, Baby!.
"I think we might be about to break a personal record for the very sexy CMAT band," she told crowds.
"We've never attempted it (the dance) with this many people, so I'm a little scared," she added.
Introducing herself, she said: "My name is CMAT and I'm literally just a young one from Dunboyne/Dublin, depending who you ask."
"This is the scariest moment of my life, but it will probably singlehandedly be the best and most amazing thing I'll ever do," she added.
Towards the end of her set, CMAT waded into the crowd to sing her popular song Stay for Something and chanted "Free Palestine" in reference to the ongoing war in Gaza.
CMAT released her debut album, If My Wife New I'd Be Dead, in 2022, and followed it up with the Mercury Prize-nominated Crazymad, for Me in 2023.
Her third studio album is set for release on 29 August.
Source: Press Association
