Marc Chagall's Four Seasons mosaic sits in the sunken Chase Tower Plaza in Chicago's Loop, wrapping around a rectangular pillar in over 250 colours. Created in Chagall's French studio, it features birds, fish, flowers, suns and pairs of lovers, imagery the artist described as representing human life, both physical and spiritual.

What makes it stranger and more personal is the story of its installation. When Chagall came to Chicago in 1974, he realised he hadn't seen the city's skyline in thirty years and modified the work accordingly. Two decades of Chicago winters then took their toll, requiring full restoration and a protective canopy in 1994.

VoiceMap's self-guided audio tours use the mosaic as a lens for understanding Chagall's long relationship with Chicago, tracing his visits from a 1946 retrospective at the Art Institute through to his cobalt glass panels installed there to honour the American bicentennial.