NME‘s The Cover star d4vd has wrapped up his sold out concert at the Islington Assembly Hall in London, which featured Holly Humberstone as a special guest.The show, which took place on May 30, saw d4vd perform an array of his biggest hits, including ‘You & I’, ‘Fly Away’, ‘Sleep Well’, ‘Take Me Back To The Sun’ and ‘Romantic Homicide’ among others.What concert-goers didn’t expect, however, was a surprise appearance by fellow musician Holly Humberstone, who joined d4vd onstage 10 songs into his setlist. For her appearance, the pair performed an unreleased song, titled ‘SUPERBLOODMOON’.Watch a snippet of the performance below, as captured by NME‘s Jeremy Abbott.