To record this I created two very different sounds. The first page is pure Aeolian, another name for natural minor. I used only the white keys. But for the second page I used a mixture of natural minor and the raised 6th and 7th degrees of the scale, which is essentially a much more modern sort of minor system. So the first page sounds older.
The rest of the story:
For centuries, Greensleeves has been associated with KING HENRY VIII, but most historians now believe ‘Greensleeves’ dates back to Elizabethan times – after the reign of Henry VIII. The song – whose full, less elegant title is ‘A Newe Northen Dittye of ye Ladye Greene Sleves’ – appears to be based on an Italian style of song that didn’t reach England until after Henry’s death.
The harmonic system:
Queen Elizabeth lived until 1603, and since the Baroque Period started around 1600, Greensleeves is written in a way that is not so different from Bach and his contemporaries. So the kind of minor used contains both the raised 6 and 7 in harmonic minor. So in the key of A minor you get both G and G#, then F and F#. In an earlier era you probably would have straight A natural minor, which today means all white notes on the piano. The older system would also default to open 5ths. So in my arrangement I used this older system for the first page, then flipped to the much more modern system on the second page. Finally, to set those two styles apart I modulated to Bb minor.
I like the effect you achieved by changing the second page. I will add this to my Wish List.