Broad Street in the centre of Oxford was in rather celebratory and victorious mood on Tuesday evening — involving a bus and a very large number of United supporters. A few hundred yards away at the Playhouse, the Northern Stage production cast emphatically set about deconstructing victory and celebration.

Oh! What A Lovely War — the original Joan Littlewood stage show — is very special indeed. Without a script, I cannot tell how much directors Erica Whyman and Sam Kenyon have updated and played around: very little, I fancy, apart from a couple of local jokes. For the play deals with serious matters of . . . well, death, actually, and wrong decisions and sad attitudes.

There is no plot as such: it is the tale of the trenches told through music and song and sudden desperate surges of sadness and grief. The cast of 12 are listed in the programme by the musical instruments they play on stage: understandably so, since apart from the ghastly senior commanders, there are no individual roles to be pointed up. This is a true ensemble production and succeeds at every level.

The idea for the original show was musically based. It is all the more impressive, therefore, that every member of the cast plays at least one instrument very well. Not only that: there is a seamlessness to the whole. Everyone successfully works, plays, changes costume and character, moves the set and whips from triumph to tragedy via bathos.

The set is important to note: remember, the cheek of the show is that we are watching a rag tag group of variety performers putting on a performance for us, a random audience; and so we see the whole of the Playhouse space decked out with brickwork, chairs and musical instruments (all of which are quickly and easily adaptable to vistas of trench warfare — believe me). This week in Oxford is the last of a long and successful tour, and my guess is that we are seeing it at its very professional best.

Is it invidious to highlight from an ensemble cast? Perhaps. Nevertheless, look out for Gary Kitching, Thomas Padden and Theone Rashleigh.

On the first night, there was a serious sound breakdown. I knew it had happened, but I was lucky and close to the stage. The cast gave their extra-all when they sang, and my guess is that the first night audience did not leave feeling short changed.