Fairly easy, very sad, beautful. The women's parts have equal range, but one tends to sit a little lower than the other. Either could be sung by altos or sopranos.
We usually sing this piece in F (one flat, started notes are D-F-A, from bottom to top).
You can also find sheet music, and midis for all the parts, (in G, a tone higher than we're singing it now) in the stuff we were working on when we were having regular singing at Cecilia's house, several years ago.