Summer is Iccumin in (Middle English)

Sumer is icumen in,
Lhude sing cuccu!
Groweþ sed and bloweþ med

And springþ þe wde nu,
Sing cuccu!

Awe bleteþ after lomb,
Lhouþ after calue cu.
Bulluc sterteþ, bucke uerteþ,
Murie sing cuccu!
Cuccu, cuccu, wel singes þu cuccu;
Ne swik þu nauer nu.

Pes:
Sing cuccu nu. Sing cuccu.
Sing cuccu. Sing cuccu nu!

http://www.youtube.com/watch?v=sMCA9nYnLWo