Vocal sensation and 'X Factor USA' judge Demi Lovato is due to perform at the grand opening of a new Microsoft store in Massachusetts next months and fans can attend for free.

Microsoft's newest retail location is set to be at the Burlington Mall, MA and to celebrate its opening on September 21, Lovato will treat the public to a live set inside the store.

A message on the Mall's official website explains that while the shop will open on September 19, the event will actually take place two days later on the Saturday:

"The first 200 people in line for the Microsoft opening on September 19, 2013 will receive two free premier viewing tickets for the Demi Lovato performance on September 21."

The ticket will allow the holder entry to the performance and also grants them access to a meet and greet with Lovato before the show.