… they would have been bade farewell by the above song.

Actually that’s the Icelandic group Arstidir performing a medieval Icelandic hymn, a cappella, in a German train station. The hymn is called Heyr himna smidur, or “Hear, smith of the heavens.” The Icelandic text is at that link; if you want to watch the video and follow along in English, here’s the translation. It’s beautiful:

Hear, smith of the heavens,
what the poet asks.
May softly come unto me
thy mercy.
So I call on thee,
for thou hast created me.
I am thy slave,
thou art my Lord.

God, I call on thee
to heal me.
Remember me, mild one,[1]
Most we need thee.
Drive out, O king of suns,
generous and great,
human every sorrow
from the city of the heart.

Watch over me, mild one,
Most we need thee,
truly every moment
in the world of men.
send us, son of the virgin,
good causes,
all aid is from thee,
in my heart.