Katy Perry has given fans the chance to hear snippets from two unreleased tracks off her upcoming album ‘Prism’.

The star took to Twitter today to share a link to an MTV Video Music Awards and Pepsi powered voting site where fans could listen to the snippets and then vote for one or the other to become Perry’s next early release track.

The star seems to be capitalising on her momentum a mere week after busting digital sales landmarks with her massive single ‘Roar’.

The contending tunes are called ‘Dark Horse’ and ‘Walking On Air’ with the former currently leading in the polls. The winning song will be announced moments before Perry takes the stage at tomorrow night’s VMAs and will be later released on September 17th.

Listen to a snippet of the current poll leader ‘Dark Horse’ below: