Jessie J has debuted a new song online after performing publicly in London.

The singer is releasing her new album 'Sweet Talker' on October 13 and she has now premiered the track 'Masterpiece'.

The Brit also performed a surprise set at the Camden Stables Market in London on Monday night (October 6).

She ran through a number of tunes with acoustic guitar accompaniment.

Jessie J also played a bit of 'Masterpiece', with the singer adding later on Instagram:

"I know I'm going in on the posting! BUT today was a moment. And I just want to share it with you all. My amazing fans shouted out sing masterpiece that Lewis and I have practiced once and never sung! I love a challenge! So yeah I did a little bit! #masterpiece #SweetTalker OUT NEXT WEEK!"

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Watch Jessie J in action below: