The title of Wayne McGregor’s ballet comes from the Latin word for ‘below’ and the work presents a portrait of life beneath the surface of the city. McGregor continued his collaborations with leading creative figures and worked with the British artist Julian Opie to stage the work. Infra had its premiere in 2008 and was dedicated to Monica Mason ‘in celebration of her 50th season with The Royal Ballet’. An LED screen runs the width of the stage, along which there is a mesmerizing flow of Opie’s walking figures. Underneath, 12 dancers move through solos, duets and ensembles. They are accompanied by Max Richter’s elegiac score, which mixes melancholy string melodies with electronic sounds. The ballet contains many arresting moments: six couples dance duets in six squares of light and a crowd surges across the stage, unaware of one woman’s private grief. Throughout, McGregor exhibits the emotionally resonant and groundbreaking choreography that has placed him at the vanguard of …