Säkkijärven Polkka is, as the name suggests, a Finnish Polka from Säkkijärvi (now part of Russian Karelia - the name of the place means "sack lake").
It's a traditional Finnish tune. The most famous performer of this tune is Vili Vesterinen (Finnish Broadcasting Company lists a recording of his performance, recorded in June 17, 1939, that has been played over and over again during the years).
The tune has played very important role in at least two cases in Finnish history.
How Säkkijärven Polkka foiled the Red Army During the WWII: Soviet Union had, of course, mined some critical places in Finland. Some of the mines they used were detonated using radio - the detonator had a radio receiver and three tuning forks. When a specific chord was played on the radio, all three tuning forks vibrated and that set off the explosion. Finns found the mines, dug around, and started playing Säkkijärven Polkka continuously on the same frequency the mines used. Because their transmitters were stronger, and the tempo of the music was fast enough and melody varying enough, the effort was very successful. Of course, the civilians thought that there was a rogue radio station somewhere and the staff had gone crazy =)
How Säkkijärven Polkka enables Information Society: Nokia used to use Säkkijärven Polkka very often as a ring tune in many GSM cell phone models (not the most recent ones, though, but it's often available for them separately!)
On kauniina muistona Karjalan maa,
mutta vieläkin syömmestä soinnahtaa,
kun soittajan sormista kuulla saa,
Se polkka taas menneitä mieleen tuo
ja se outoa kaipuuta rintaan luo.
Hei, soittaja, haitarin soida suo
Nuoren ja vanhan se tanssiin vie,
ei sille polkalle vertaa lie!
Sen kanssa on vaikka mierontie
Siinä on liplatus laineitten,
siinä on huojunta honkien.
Karjala soi - kaikki tietää sen -
- Repe Helismaa, 1953
The lyrics have been written after the war, and just try to say how cool Karelia was... Finland lost Eastern part of Karelia to Russia after the war.