A bit of rubato

This week we spent a good chunk of our time learning our Blood Brothers medley. I don't know the show myself (and those who know me won't be remotely surprised about that) but it's got some cracking tunes in it and a very moving closing section.
Anyway, above the lines for parts the instruction states 'rubato'. Despite having learnt piano and clarinet at school and having been in the school choir (as well as having a music teacher for a Mum!) I had never come across this particular word before, so thought that I'd have a look and see what it meant.
It was one of those times when the mobile internet proved its worth! Doing my very best not to be seen by our musical director, Terry, who does get cross if we're not focussing on his direction, I typed rubato into  Google to see what it meant.
It seems to be that rubato is one of those hard phrases to define adequately in a few words. Essentially it seems to mean rhythmically. But then the reality appears to be that it's the bit where you sing it with your own rhythm, to give life and movement to a particular piece. In other words you make it your own!
So how does that work when you're singing as part of a chorus! Does everyone sing it their own way? Or does your MD decide what it should be and the rest of the company just toe the line like usual?
I guess that I'd consider that rubato was summed up in our Miss Saigon medley last year in the Sunlight and Moon section. Adela just did something with her phrasing in the line "We have been blessed, you and I" that was amazingly moving. And I guess that was rubato!
For BMT this week, the rubato was managing the short notes on the first syllable of seven before we ran into the native American woo, woo, woos! The ladies got there in the end.
For us guys, I think we managed to give it a good old dose of rubato - but that was a lot more about adding in our own rhythm and style. And quite possibly in the parts where we shouldn't have done.