Err, we actually still chant that
I do believe that "Fighin' Joe Leidig" started that chant back in the day (I remember him starting it up while being held up by the cheerleaders when I was a Plebe).
It went like this:
Dant: "I"...Brigade: (echos) "I"
Dant: "I believe"...Brigade: (echos) "I believe"
Dant: "I believe that"....Brigade: (echos) "I believe that"
And so on. At the very end, the entire Brigade would start jumping up and down chanting the whole thing over and over again.
Nowadays, no one in the administration "makes" us do it. Normally someone (normally from the "Pit," the place where the wrestlers/non dressing football players sit in the Brigade seating area) starts it up and we go along with it. We only chant it when we have have the game all locked up (like 2 min left or something like that).