Ben Duke belongs to a class of younger choreographers who have decided to flout the convention that dancers should remain silent on stage. Liberating their voices is by no means a new phenomenon (in 1961 Frederick Ashton had Svetlana Beriosova speak verse by Gide in his sadly forgotten Persephone), but it’s one that particularly suits our culture’s dislike of rigid genres, and Duke makes playful use of it in the double bill entitled Death Trap that makes up Rambert’s current tour, which lands at Sadler’s Wells on 22 November.