One Direction Share Best Song Ever Audio

One Directionhave released the full audio for their new single Best Song Ever.

The boy band have debuted the eagerly awaited track via YouTube - tipping their fans off about it on social media sites.

The track is the promotional single for their 3D movie This Is Us and is set for release on Monday. It is written by Ed Drewett, Wayne Hector, John Ryan and Julian Bunetta,

Each of the band will play a different character in the video for the track - with young Niall Horan ageing dramatically for the job.