I'm off to London on Wednesday for a meeting in the evening. As I have the day free, I was going to head down early and catch a matinee.
I know about the various apps etc. where you can get fairly last-minute tickets to theatres - but when I lived in London, I used to turn up to the box office an hour or so before the show started and ask if they had any standby tickets, which I used to be able to pick up for about a tenner (often premium seats too!).
However, this was about 20 years ago! Is this still a thing, or is it all digital these days?