Avicii poses for snaps ahead of his DJ set at this year's #CapitalSTB This image appears in the gallery:Little Mix And Fifth Harmony Lead The Summertime Ball Red Carpet Arrivals 21. Avicii poses for snaps ahead of his DJ set at this year's #CapitalSTB Picture: PA 23 images See the full gallery: Little Mix And Fifth Harmony Lead The Summertime Ball Red Carpet Arrivals