1959 – the trials of selling a house; 2009 – the trials of buying the same house; and the social repercussions of both. Bruce Norris’ smartly clever play is a delight and I’m guessing it’s challenging fun for the cast. Each cast member has two roles, one set in 1959, one in 2009 and it’s as pacey as it can be with characters required to talk over each other, no shying away from difficult subjects, lots of laugh-out-loud moments and some uncomfortable buttock shifting.

“Clybourne Park” is a new relative to Lorraine Hansberry’s 1959 play “A Raisin in the Sun” with which I regret I am not familiar, so I can’t comment. The two plays share a character (structural similarities with “Hamlet” and “Rosencrantz and Guildenstern are Dead” are noted in the programme), that of Karl, who wants to keep the neighbourhood white in Hansberry’s Play, and who in Clybourne Park is friends to Bev and Russ who are selling up and moving out, and has similar concerns.

You may well have heard that Clybourne Park is a play about racism, and it certainly is! But while taking nothing away from the impact that definitely has, its multi-layered characters additionally pose other interesting and difficult questions of how people from different backgrounds behave with each other. Yes there is neighbourhood-based racism courtesy of Karl who is aghast to discover the identities of the people moving into Clybourne Park. But other levels of insensitivity include a deaf character who is the unwitting subject of prejudicial language; and there is even the crass condescension of Bev to her daily help Francine, hectoring her to take possession of a useless kitchen implement that she doesn’t want, is far too difficult to pack, and is too good to throw away. Then we move to 2009, and people are much more enlightened. Aren’t they?

The play is at times hysterically funny – that kind of humour which catches in your mouth as you guffaw as you realise the awfulness of what you’re laughing at. Sometimes you sense a general unease in the audience at the non-politically-correct nature of some of the lines, where the laughter slowly gathers momentum like a Mexican Wave as you realise it’s acceptable to vocalise your amusement. But you’re embarrassed too.

It’s a very clever play because it’s easy to make assumptions as to who is being racist or insensitive about whom and why, but life is rarely that straightforward, which makes the humour even more cringey. There’s a key segment in the second act when Steve, played by Stephen Campbell Moore blunders his way into an ill-advised joke-telling session where there’s no turning back. It’s all beautifully performed, and the social balance at the beginning of the conversation is shattered by the end of it. It’s very easy to see oneself somewhere in that situation, whether as the joke teller, the audience, the offended or the horrified onlooker. But it’s much more than a series of racially-challenged comments; it’s a very well constructed play which will challenge everyone, comparing attitudes fifty years apart, and with a hark-back to 1959 at the end, tying up the loose ends and satisfying in its completeness.

There are no obviously starry roles in the play and the whole cast turn in great performances, but especially memorable is Sophie Thompson’s 1959 Bev, the height of middle-class respectability and charitable to a point; I felt that, 20 years on, transplanted to London and a few gins later, she could turn into Mike Leigh’s Beverly from Abigail’s Party. Lorna Brown’s sophisticated 2009 Lena subtly manipulates the whole of the second act from her central position and it’s a stunning performance, particularly in contrast with the uncomfortable Francine of the first act. I also really liked the willing but rather hapless 1959 Albert played by Lucian Msamati, doing his best to do the right thing under trying circumstances.

I’m very pleased we got to see this play before it closes but I find it impossible to think that Clybourne Park is going to go away so soon. It was a pretty much full house and is surely ripe for a tour. It’s got a lot to say and it does it extremely well!