This performance is exactly the one that troubles me the most. Being a big fan I got myself pretty close and honestly I can't believe she could sing that perfectly at that age. I'd love it to be true but it was sooo perfect. Yes including when I watch it back sober. Proper band yes but surely augmented vocals.
There's a rumour of 1975 doing that new Come Together event in Newcastle alongside Robbie Williams & Kings of Leon, so that would count as a part of it. Whether that's enough by itself is another query.