They’re the Icelandic folk group Árstíðir. On this particular night, they had just finished a concert in Wuppertal, Germany, and were making their way back to their lodgings when they were struck by the station’s perfect acoustics. Its arched, stone ceiling created a cathedral-like environment.
Boosted by the success of the evening, the six men broke into song. A hush immediately fell over passersby, some of whom almost certainly missed their trains to stay and listen to the beautiful harmonies.
Despite the fact that this song, “Heyr himna smiður” (English: “Hear, Smith of heavens”), dates to around 1208 and the Wuppertal Hauptbahnhof station was built in the mid-19th century, the sound and the space seem perfectly suited to one another. At one point a public announcement is piped over an intercom. Instead of ruining the music it magically weaves a new voice into the harmonic tapestry.