Just happen to find this link on youtube. It is from an old film that I believe I made reference to in one of the discussions about old bata drumming. This is from an old movie called "Affair in Havana" from 1957. It shows a young Ceilia Cruz singing to Obatala and Agayu with old school bata drummers. The clip is very dark but I believe the iya player is Giraldo Rodriquez. While it does not show real ritual it does show real bata drummers in an age long since gone.