Having looked through a bunch of posts in this thread, I wondered why they were all so clean. It seems the forum rules require it, and today's military has become PC.
This one is from USAF Basic Training. A "rainbow" is a new recruit who has only been issued a PT shirt and is still wearing civvy trousers & shoes. The next cadence is sung by squadrons (who have full issue and have washed it at least once) passing a rainbow squadron.
TI: Rainbow, rainbow, don't be blue.
Squadron: (repeat)
TI: I was once a rainbow too.
Squadron: (repeat)
TI: Sound off.
S: one, two.
S: three, four.
TI: Bring it on down now.
S: one, two (on Lefts; (rapid L/R) three, four!
There were several variations on this one:
I don't know, but I've been told.
Eskimo p***y is mighty cold.
There were a bunch of Jody's too.