Global Citizen Live is being shown on BBC1 Saturday evening into Sunday morning.I looked up that quote, and with that I was able to trace things back to the web site of some sort of celeb charity event being organized to take place in a number of cities in various parts of the world. It's being run by some organization called "Global Citizen". I hadn't heard of either the event or Global Citizen until now.
There are apparently going to be loads of celebs in attendance. There are a lot of musicians, so it's possible that it's a charity concert event. I have only heard of a few of the musicians being headlined, but that doesn't mean much as I think that most pop music is rubbish anyway.
So the two of them will be there. Whether they get a chance to hold a microphone to fill time between between bands setting up is something that I don't know.
It's a benefit concert with the theme of global vaccination. It will be funny as hell if it turns into a COVID-19 super spreader event.