Kylie Minogue surprised a pair of eight-year-old twins by singing their late mother's favourite song with them.
A video of Lauren and Sophie Cripps singing Kylie's hit Dancing to their dying mother Alex went viral earlier this year.
After seeing the video, Kylie arranged for them to see her backstage at her concert at Blenheim Palace on Sunday.
Their father, Lee Cripps, from Thatcham in Berkshire, filmed the surprise and said Lauren and Sophie were "thrilled".
Alex Cripps died at home on 10 January five years after being diagnosed with a brain tumour.
Her husband Lee tweeted Kylie a video of their daughters Lauren and Sophie singing Dancing to their mother a day before her death.
The Australian pop star tweeted him back thanking him for sharing the "tender moment".
She added: "I'm so touched and so very sorry for your loss. Sending you and your girls lots of love."
However, what Mr Cripps had not told the girls was that he had been in touch with Kylie's management and arranged for them to meet.
Mr Cripps said they were invited backstage following the concert and the twins spent about 15 minutes chatting with Kylie.
"It was a surprise I had known about for a few weeks," Mr Cripps said.
"It felt like Kylie had all the time in the world for the girls. They were thrilled."
He said the moment Kylie started singing with them was "moving" and "unforgettable".
Sophie added: "It's not every day you get to sing Dancing with Kylie... it was a really big surprise and really fun."
On Facebook, Kylie said: "Absolutely loved meeting Sophie and Lauren and getting to sing Dancing with them! Thank you girls!"