'Mirie it is while sumer ilast' is earliest secular song surviving in English. In the 20th century there has been a 'standard' accepted version of this song. However, I have revisited the only manuscript in which it appeared and found that neither the music nor the words in the text are as they are sung by early music revivalists. You can see my stage-by-stage reconstruction and read about the social context of the song, with a video accompanying the reconstructed song on medieval harp, at http://earlymusicmuse.com/mirie-it-is-while-sumer-ilast/.