Alternates, understudies, standbys, covers - I need stories!

At Matilda London I once saw Ashleigh Drew (female swing) go on as Bruce Bogtrotter for the final song, Revolting Children, as the main Bruce got ill and the standby had already gone home.

Could you please explain that Equity rule a bit? Why there’s such a requirement?

If a show hasn't started or restarted (in the case of a show stop) with in 45 minutes of the start time/stop time. It should be cancelled and all patrons refunded. It's just due making sure the actors and audience get home at a reasonable time as shows already finish late enough. Or in the case of what I saw it's to make sure there is a still a sufficient break between a matinee and evening show for the actors.

Awww I was at the same Les Mis show where Jonny went on as Marius. Also to add the swing/dance captian Oli did a lot of the Marius track ensemble stuff you seen from Convicts through to Who am I.

Had forgotten this one until today:
The previous Les Miz US tour would take breaks in the summer because it wasn't selling as well in the last few years of its run, and about half the cast would rejoin in the fall. I saw the final performance before the break one year, and David Michael Felty (Brujon and an amazing Valjean understudy) had already shaved off part of his beard until he found out 10 minutes before the show that Randal Keith was going to be out (I think due to injury). DMF hastily drew back part of his beard for the prologue, but it was totally lopsided. I suppose if you were sitting far enough back, he just looked more smudgy on one side, but we were really close and very tickled by it all. By the time the factory scene came along, his facial hair was symmetrical again. I think the rest of the show basically had a mostly goateed Valjean rather than a bearded one.

The come from away standbys have a hard job.

Every actor in that show is playing a few characters anyway. When you are covering six tracks then you could be learning in excess of 20 different characters.

Sydney, Australia

There was the woman working on box office who went on in Knights of the Rose last year when there was no one else. Definitely a rarity. Here's a link to the story www.google.com/amp/s/www.bbc.co.uk/news/amp/entertainment-arts-44979238

I once went to the theatre and enjoyed a performance irregardless of principal, cover or understudy changes.
Wait, thats every time I've been to the theatre.

Well you asked us to "share with me all the unusual stories you have that related to the topic" of "principal-cover-stanby-alternate differences and how it all works in different shows".
My point being that some people really track, focus and study the understudy circuit whilst others remain inattentive to it - which I find quite interesting and salient to the topic.

I've a couple of times seen the director go on with a script - once, rather clunkily in Side by Side by Sondheim at the Library Theatre in Manchester.

I guess the most famous understudy story is that Shirley Maclaine was on for Carol Hainey in The Pajama Game when film producer Hal Wallis was in the house and he instantly signed her up for Paramount

Did anyone see Jeremy Northam's Hamlet? (he was Daniel Day-Lewis' understudy)

In terms of a lucky understudy, I'd say that Philip Bertioli was one when he got to play Billy when they filmed "42nd Street", I'm sure that's not often happened that an understudy has ended in in the filmed performance. Obviously illness/injury/other reasons do happen but that was definitely a bit of luck for him.

This is possibly not quite what you were after but it's a good example of just how quickly swings have to be able to learn (and yes, I do know people have to learn things in a couple of hours in emergencies, but this is I guess a more standard amount of time, but still doesn't feel like much). George Olney (all this info is from his twitter/instagram account) found out he had got the job as a swing in "Fiddler on the Roof" on the 14th of June. He then had his first rehearsals on the 17th, he then did 6 or 7 rehearsals before going on for the first time on the 28th. Today, less than a week after his first show he's already splitting tracks. Definitely a busy life if you're a swing! I don't think it's the most complex of shows but I am sure it's way more complicated than it looks.