I'm paying attention to Bruce--but just to look for mistakes. How long was "Greensleeves" lost? It was known before the late 18th century, since according to this site, it was Air 67 in John Gay's
Beggar's Opera(1728) and was used in "a number of songs" in some (roughly contemporary?) source called Pills. Could you have meant the late 17th century?
And if "Greensleeves" was so poor, when did it become so beautiful?
Okay, Bruce, thanks for posting some real historical data. A little more: the bass line seems to be that of a dance form called the passamezzo (or the very similar romanesca), according to many sources, such as this one (scroll down to "passamezzo"). I am not suggesting that the origin might be Italian!
In fact, today a friend of mine happened to send me the following quotation on a distantly related subject. The last sentence is my favorite.
'I'm often asked the question, "Do you think there is extraterrestrial intelligence?" I give the standard arguments -- there are a lot of places out there, and use the word *billions*, and so on. And then I say it would be astonishing to me if there weren't extraterrestrial intelligence, but of course there is as yet no compelling evidence for it. And then I'm asked, "Yeah, but what do you really think?" I say, "I just told you what I really think." "Yeah, but what's your gut feeling?" But I try not to think with my gut. Really, it's okay to reserve judgment until the evidence is in.'
- Carl Sagan, The Burden Of Skepticism,
The Skeptical Inquirer, Vol. 12, Fall 87