A rather more elaborate one I heard in a radio interview with the composer Fela Sowande: British missionaries tried translating the hymn "O Come All Ye Faithful" into a tonal West African language (Yoruba, I think). Their translation was fine, if you just read the text. If you sang it to the standard "Adeste Fideles" melody, the pitch pattern of the tune threw all the tones off and changed the meaning of the opening line to "go out and dig for groundnuts, you who are fond of pissing".