John Legend: This busker was singing one of his hits. Little did she know that he was in the audience

A busker in the US had a chance encounter with John Legend - while singing his hit song All Of Me.

The Grammy winner was visiting Faneuil Hall in Boston with his family before his concert on Sunday night when he stopped to watch street performer Radha Rao.

The singer was performing his hit song and impressed Legend enough for him to leave her a tip and give her a hug.

The 22-year-old didn't recognise him at first - he was wearing a mask and she didn't know he was in Boston.

Ms Rao, who has grown up in Boston and spent some time living in Hyderabad, India, told Sky News that "it was a wonderful surprise".

"It was something I didn't expect at all but it was a wonderful surprise to have. It's not common that you happen to be singing an idol's song and he's there. It was a special experience," she said.

While the singer, who recently graduated from Boston University, was nervous when she spotted Legend, she said she kept singing.

"I am a big fan and he is a big inspiration. I am going to always continue to sing that song. It's a fan favourite and one of my favourites. That memory will continue to help me perform," she said.

Ms Rao said Legend expressed his sentiments to her music and voice, and he also thanked her for singing his song.

The song is a regular part of her two-hour set at Faneuil Hall, after trying her hand at street performing for the first time in August because she wanted a new experience that was spontaneous and colourful.

While Ms Rao is a relative newbie to street performing, she has been singing from a young age - drawing on the influences of her Indian heritage.

Subscribe to the Backstage podcast on Apple Podcasts, Google Podcasts, Spotify, Spreaker

Her mother is a classical trained Indian singer and she uses influences from that on her music, which she describes as western with an Indian fusion.

Since graduating from university, Ms Rao works full-time at a music tech company and spends her spare time gigging and making music, which she says is her "true passion".