I know this has been around for quite some time but I just heard this and now I’m totally a fan.
The girl in the animation is Orihime Inoue from the anime Bleach twirling a leek to a traditional folk song “Ievan Polkka” by the Finnish quartet Loituma, taken from their 1995 debut album Things of Beauty.
This are the lyrics, sort of, if you wanna try singing along.
yaa tsi tsup ari dik ari dull an dik ari dill an dits tan dool
la dippyduppy dull la roop uttyroopy la goorigan gook aya gittygangool
arup cha cha adippydappydill la baritztandill lan den lan doe
a barik kata barip pari baribadeebadeebadee standen lan doe
ya baril las ten lan day a doe la babadeadevadevadevaduv ya vou
what is that little las day lan doe badakadagadaga doo doo day a doe
(warning: extremely addictive)