Judging from the change in sound of Neil’s voice I actually think the musical performances were not live-to-air, but pre-recorded. Neil’s comments in between were live.
Edit: Neil confirmed this during the show.
And not wanting to be nitpicking but the tribute in the aftershow was for Tony Allen, who played with Fela Kuti.
That's corrector musical performances being recorded. Neil did explicitly say this, because they were recorded own a new piano in another room.
The Mixer live feed displays a particular icon that shows the track is a recording.