5 Seconds Of Summer Serve Up "Pizza" in Madrid

It may only have been intended to be an inside joke of the band, but fans love 5 Seconds of Summer's 37-second b-side "Pizza" and the Aussie four-piece surprised fans at their sold-out show in Madrid to a performance of the track.

A fan-shot recording can be viewed below.

Remaining dates and ticket information for the band's "Rock Out With Your Sock Out" world tour can be found here.