Whats the oldest traditional song in your country?
For germany that would be the Palästinalied made by Walther von der Vogelweide. Written around 1200 its the oldest german piece of music that survived with lyrics and melody.
Kristen, juden und die heiden
jehent, daz diz ir erbe sî.
got müez ez ze rehte scheiden
durch die sîne namen drî.
al diu welt, diu strîtet her:
wir sîn an der rehten ger.
reht ist, daz er uns gewer.
Christians, Jews, and heathens
all say that this is their patrimony.
God must decide this justly,
by his three names.
All the world is warring here;
we are pursuing a just claim,
so it is just that He grant it.
Still true even after 800 years.