Online media files have this event have been coming out for two years, but the best I've seen are from Gloria.TV, which has the entire liturgy from top to bottom online. As you can see from this clip, it was traditional back then for commentators to talk over the music just as now. I believe the Credo that the choir sings here is a Missa Papae Marcelli by Palestrina. It sounds a bit scattered to our ears but there is still something extremely touching about this.