Busker stunned after John Legend appears in audience while she's performing his hit song

A busker singing John Legend's hit 'All Of Me' was shocked when she noticed the Grammy-winning musician watching her performance. 

Footage of the moment has gone viral on social media, showing singer Radha Rao performing with her keyboard on a Boston street as Legend watches on appreciatively. 

"Why are you in Boston, Mr Legend?" she asks mid-song, in one clip shared on TikTok. 

In her own post on Instagram, Rao said she was "grateful" to have gotten the opportunity to sing for the "incredible" Legend and his family. 

After Rao finished the song, Legend broke into applause with the rest of the gathered crowd before making his way up to give the budding musician a donation and a hug, prompting cheers from onlookers. 

Speaking to The Boston Globe, 22-year-old Rao said she couldn't believe what had happened. 

"What are the odds that John Legend is in town, in the area you're performing, as you're singing his song? Beyond believable.

"A lot of people tend to ask, 'Did you play it because he was there?' And the answer is no," Rao said.

"I was playing it, and then he happened to appear after I started the song, so it was quite a shocking experience." 

In another interview with NBC, Rao called the experience "nerve-wracking", but said she "enjoyed it immensely", adding that Legend went on to thank her for singing his song. 

"He was so incredibly humble and encouraging to local artists. I look up to him immensely, and I love that he plays acoustic instruments like I do," she said. 

Legend was in town with his wife Chrissy Teigen and their two children, where he was scheduled to play a concert later that night.