either massively improve on or completely re-imagine the recorded performances.

I watched remember seeing them on Italian TV many years ago.
It was a talent show and you could see how the participants slowly come to terms with what they're hearing and realise; "Oh shit, this is the level".
Bellissima e bravissima.





And then there's this early rendition of "Hey Now" (2014), with the incredibly long ~3 min intro of just the word "Hey" over and over again.
Perhaps not quite as polished as they are now but magical just the same.