Here's little Yuki Kaai singing a very cute and calming version of both the original (Loituma) and 'nonsense' (Miku) words to Ievan Polkka. The visuals are just a range of cartooon representations of the performer.
There are no English words, but this is just two minutes or so of fun and delight, so understanding the words is unnecessary. Indeed, it's probably better this way, for two reasons (they'd be a distraction, and they are a bit 'adult' in tone).
Yuki (meaning 'snow') is the youngest Vocaloid to date, pitched around nine or ten years of age; and her voice just works so well for this song – although as I hinted above, the original song, if translated, isn't quite the sort of thing one might expect someone of such tender years to sing...