Dreamgirls - Savoy / UK Tour

Welcome to the board, Colin! Previews essentially give everyone time to tweak the show, play around with things a bit and see how the audience responds (both in terms of reaction on the night but I've known them do surveys of some audience members before, too), and try to make sure it's as tight as possible for press night and the critics.

In this case, I doubt it'll change a great deal. For a new musical, they may even cut songs, insert songs, change the order of scenes and change dialogue to some extent in previews,  but that's because the musical itself will not have been done before.

This musical is tried-and-tested and comes with a set book/dialogue/order etc. which has been worked on for years before this point and very honed, so it'll more be a matter of everyone settling into the performance, working out costume/scene change issues, and maybe a change of costume/wig/lighting/emphasis here or there, but nothing too dramatic. Having said that, you never know and late changes can be made to well-known pieces, but I seriously doubt it in this case.

I've been to a fair number of previews, and in general I wouldn't have known they were pre-press night performances if I hadn't already known. They are still selling expensive tickets to a show, so they know you expect to see something pretty much there or thereabouts and worth the money. There can be a real buzz around previews as the audience knows they are among the first to see something, and the actors are very fresh, so they can be wonderful to attend. I hope you have a great night and report back to all of us on how it's looking!