Greensleeves - I always thought this was dorian? Though it changes at the end. (Great lyrics, thanks for that!)
It could be. I'm not an expert on modes v. keys...
Wikipedia has the following (albeit unreferenced) statement:
The earliest known source of the tune (Trinity College, Dublin ms. D. I. 21, c. 1580—known as "William Ballet's lute book") gives the tune in the melodic minor scale.
The link to said book was broken though.
Cannot for the life of me find the full set of those parody lyrics now though...
By the way, it should be noted in this thread that there's not a "lack of material that demonstrates the classical melodic minor scale in a way to justify to students", it's just you need to look beyond instrumental music and think about songs.
I have found that we largely teach/learn the harmonic minors first because they are the same both ways and therefore easier to play, not because they're actually the most natural pattern from an aural/theoretical point of view. If I was teaching minor keys and scales from a purely aural and theoretical point of view, I'd be teaching them natural -> melodic -> harmonic. The harmonic scale isn't a "real" scale (compared to the natural & melodic minors and major scale), so much as a theoretical construction to demonstrate how chords are usually built up in a minor key. It really is an almost unnatural invention, but we convince ourselves and our students it's the "real" minor scale by teaching it first.
We certainly shouldn't need to "justify" why melodic minors have to be learned and understood.
Most Western songs in a minor key use the melodic minor . It's the more comfortable of the two scales to sing and create melodies from. Very few songs use the harmonic minor (mostly weird modern stuff), although lots of folk music does use the natural minor. There's not a lack of resources, but you do need to think beyond graded instrumental music to find good examples of melodic minor in use.
I think it's actually harder to find examples of the harmonic minor scale in use in real music outwith the construction of chords...
(Oh, that got ranty... but I really hate the idolisation of harmonic minors, they sound exceedingly unmusical to me, coming at them as a first study singer)