Definition of "jody"

I watched the formation move away and listened to the PT leader begin to call out a "jody," an Army song to help units run in step in formation

1995, James E. Kennedy, About face: a gay officer's account of how he stopped prosecuting ...

I walked back to the dorm as my team ran by in formation singing a jody about their last day.

2011, Mark Lauren with Joshua Clark, You Are Your Own Gym: The Bible of Bodyweight Exercises, page 5