In the installation Forty Part Motet (2001), Janet Cardiff gathers eight sets of five speakers, each of them positioned in a large semicircle. Each speaker reproduces the voice of one member of the Salisbury Cathedral Choir (United Kingdom), recorded by individual microphones before the song starts and during its rendition. While going through the installation, the spectator can come closer and move away from the speakers to hear the different voices, as well as to notice the different combinations and harmonies among them.

The piece chosen for the recording is called Spem in alium nunquam habui [My hope lays in no one else], composed by Thomas Tallis in the 16^th century to celebrate the fortieth birthday of Elizabeth I, Queen of England, in 1575.