I heard the lyrics or a varient used as marching cadence and that is most likely where they got their start. Most cadences come about from the spur of the moment and get a dapted as time progresses. As you likely know, Horace, cadences are basic call and response songs set to a march step. The version in the DT is most likely a green beret or Phoenix varient although put stock on the former. I would have to say it originally started as an Air Force or Naval Aviation cadence Although it could be MArine Corps issue (Marine pilots are considered NAval Aviation.) I hope it helps. Kindest reguatds, Neil