Note the semi-colon in my post, which separates the statements. I was not suggesting that the song was written in the 18th century; merely providing a well-known and (to my mind) pertinent example of an earlier pronounciation of the ea sound. The sound as Morley probably pronounced it is harder to represent without using phonetic symbols, which is why I used the tea/tay example. He himself will never have drunk tea as we know it.