New York City subway riders hold impromptu dance party after Robyn concert

NEW YORK -- These New York City subway riders were not dancing on their own!

After Swedish singer-songwriter Robyn headlined Madison Square Garden Friday, hundreds of concert-goers poured onto the 34th Street-Penn Station subway platform.

Suddenly, the fans broke into song and dance. Video posted to social media captured passionate renditions of "Call Your Girlfriend" and "Dancing on My Own."

"This is what music is ABOUT," a Twitter user tweeted in response to one video.

Robyn responded to fans on social media, saying she was "overwhelmed" by the display.

"I can't believe the love in this subway station. Thank you New York," she said.

Robyn's concert was a part of her nationwide "Honey" tour.