PAA
Thanks
Though
a. Ive never quite seen what the Taz says being done. (I assumed he was talking when preparing the Chasan by putting ashes, but granted it could be after the chupa)
b. I only mentioned it becasue it is something that we can see unfolding. Even if it is a reincarnation of an older perhaps similiar minhag. 20 years ago (almost?) nobody had it at their Chupa, Slowly people began doing it. Now (almost?) every chupa has it sung (I havent been to a real chasidish wedding in a while so I dont know about them)