Taylor Swift has invited a host of famous faces on stage with her during her 1989 tour, but fans in Glendale, Ariz., may have received the most special moment of all. Swift decided to perform a rare tune she wrote in 2011 for 3-year-old Ronan Thompson, who passed away from neuroblastoma.

Ronan’s mother, Maya Thompson, lives in the area and was attending the concert, so Swift took the opportunity to perform the song — which she had only performed one other time at 2012’s Stand Up to Cancer benefit show — as a tribute.

Swift introduced the song by talking about what an inspiration Maya has been not only to her, but others by sharing her story on her blog.

“I think that, in my opinion, one of the greatest things that a human being could ever do is to go through something absolutely unbearable and then share their experience with the world,” Swift said, speaking directly to the mother who lost her child. “And I think, the braver you are, the more brutally honest you are."

“The thing about childhood cancer is that it’s really really hard to talk about,” she continued, addressing the crowd. “And it’s really not something that you bring up because it makes everyone really, really upset, but the fact that she brought it up … She had this blog called Rockstar Ronan, and I would read it every night. And in it was this account of what it’s like to watch cancer take over your life. Since then, I’ve had cancer hit really close to me in my family. So because Maya’s right there, I would like you to give her a round of applause, please.”

Swift's mother, Andrea, was recently diagnosed with cancer.

The singer says she lifted many of the lyrics from Maya’s blog itself and therefore listed her as a cowriter on the track. All proceeds from the song’s sales benefit childhood cancer research.

After a heartfelt intro, Swift sang the emotional song with tears in her eyes, accompanying herself on an acoustic guitar on a catwalk high above the crowd, alight with swaying cell phone flashlights (in lieu of the traditional lighter). Maya later a photo of her family with the singer backstage, expressing her gratitude and love for Swift.

Swift has become known for her compassion towards fans and consistent efforts to go above and beyond to create special moments for them, attending bridal showers, writing to fans on Tumblr, visiting them in hospitals and more. Forbes recently named her as one of the top-earning celebrities in the world, thanks to the wild success of 2014’s 1989. She’ll continue her 1989 World Tour through December.

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