The sheet music I have has this in "C" (starts on A and D, ends on D, no sharps or flats in key signature). The Darton singers usually transpose it so it starts on C and F, and has 4 flats; so these midis are at that pitch.

• both lines [3]
• both lines, an octave down [4] (for male singers)
• top line emphasised [5]
• top line emphasised, an octave down [6]
• bottom line emphasised [7]
• bottom line emphasised, an octave down [8]

It works well wherever is comfortable for the singers: starting a fifth apart, in adjacent voices.