This devotional hymn was originally written in 1208, but its mesmerising beauty is completely timeless – as this spontaneous performance in a station in Germany proves.
Sometimes the most profound moments of music are the simplest.
An Icelandic indie-folk group walked into a resonant space in a train station in the German city of Wuppertal – and then this happened:
The group is Árstíðir, and the music is the 13th-century Icelandic hymn "Heyr himna smiður", and adapted by Þorkell Sigurbjörnsson, one of Iceland's most important 20th-century composers.
Following the success of this simple moment of music making (the video has been viewed 5 million times), the choir recorded the song with Anneke van Giersbergen – you can find out more about that here .
And if you fancy recreating this at your local train station, here's the sheet music of the hymn .