cuckoo, cuckoo... what do you do? in april, I open my bill. in may, i sing night and day. in june, i change my tune. in july, far, far i fly... in august, away! I must... cuckoo, cuckoo... what do you do? in april, i open my bill. in may, i sing night and day. in june, i change my tune. in july, far, far i fly... in august, away! I must... cuckoo, cuckoo...