Ariana Grande's first interview since last year's Manchester Attack was an emotional affair, but during her appearance on Late Night with Jimmy Fallon, she also took the time for a more lighthearted segment.

Fallon had gathered together a number of Grande's biggest fans to perform a cover of her song 'One Last Time', under the premise of it being a fan video to show her - but little did they know that she would be listening to them.

Needless to say, their faces when they realise that it's really her are priceless.

Watch it below: