Though im not sure of the origin of the upbeat version....the hoop suporters love it!
during the course "WOHH BABY LET THE FREE BIRDS FLY" is yelled after "Where once we watched the small free birds fly"
then... after "our love was on the way" some ppl shout "Sinn Fein" and then after "we had dreams and songs to sing" others scream "I.R.A!!"
I dont know if those are the same ones you heard, but at my Celtic club those are the call back lines.
Slàinte!
Sean
Ourselves Alone!