“Ievan Pollka” is one of the most famous Finnish songs in the world. Written in the 1930s to a traditional Finnish polka tune, it became popular after World War II, then disappeared for a few decades, and later resurfaced again after a Finnish quartet called Loituma performed it a cappella. It’s also known as “Loituma’s Polka.”
If you find yourself wanting to sing along, you can always read the lyrics here: