I'm deeply grateful to my commenters for their help . . . but I have to say that it wasn't quite what I had in mind.
What I was really trying to get details of was of liturgy that people who couldn't attend the Holy Father's events could go to at that time . . . not afterwards.
I did know that there was TV coverage; and also available online . . . but I'd heard more than idle rumours of some large-scale Masses to support the Papal events; and it was those that I was hoping to get more information about.