Pop star Jessie J has launched an online quiz for fans to win tickets to an upcoming concert.

The Price Tag hitmaker will perform in London on 23 September (13) as part of the 2013 iTunes Festival, and she is giving followers a chance to attend the show for free.

Fans have to answer a question about the lyrics to her new single, It's My Party, and correct answers will be entered into a draw to win tickets for the gig.

Providing a link to the quiz on Twitter.com, the singer writes, "Who wants to see me live at iTunes Festival on Sep 23rd?? Got some tix (sic) up for grabs."