The melody is in the tenor part in traditional shape note notation, and originally there were only three parts; the alto was added later. In Shape note gatherings, both men and women will sing the various lines, picking their favorite octave.
The tenor is written in treble clef and is sung an octave down (by the guys, anyway) and the bass is bass. No tenor clefs or such. Let me look and see if I have a 4 part "Star in the East"
If we can't find one, you could just have one woman do the tenor as written. The alto parts tend to be boring, filling in the third, as they are wont to do. Let me look.
Blessings,
one of the other Barbaras