6 Part Harmonies?

J.Shave said: "Hi! Five of my other friends and I are looking for songs (doesn’t have to be musical theater) with at least six characters/vocal parts/harmonies.
Currently we have been working on “Ex-Wives” from Six and would love to do more- Thanks!"

Interestingly enough, even though the song is sung by six people, the harmonies do not go beyond four different notes at a time (according to the official PC score of the North American premiere of the show). Ironically, we only hear a few short glimpses of actual six-part harmony throughout SIX.

This would still suffice for you though!