All my classes are divided into four groups. I can't tell you how well this works - they can make four small-group circle, four lines in front of the projector, or a four-sided square we mold into a circle.
So, it isn't a surprise that, when I wrote this Thanksgiving speech-to-melody piece, I wrote four parts. I used a similar piece with my 2nd graders (using Mi, Sol, and La). This one is Do pentatonic-based (of course) although there isn't a "Re" in the piece. I use it for 3rd (we look at everything - the structure, the rhythms, the pitches on the staff, etc) and 4th/5th (review/just for fun and also a composition extension - I ask each group to come up with a new four-beat pattern for us to use).
I have a whole plan of action, but basically we chant the lyrics, add unpitched instruments (see below), sing the lyrics, then add pitched instruments (I use metalophones, they sound more "festive").
Line 1: hand drums
Line 2: jingle bells
Line 3: wood blocks
Line 4: rhythm sticks