If there were any doubts that Stephen Sondheim is theatre royalty then this year's extended celebrations for his 80th birthday proves it. But then if anyone deserves to be celebrated it's our Steve.

The Donmar are paying tribute to the great man with their production of PASSION but they also are honouring two previous Sondheim shows they have staged with concert performances at the Queens Theatre with the original cast members. The first show was very appropriate for the subject of looking back, MERRILY WE ROLL ALONG.

Based on the 1934 play by George S. Kaufman and Moss Hart, the story charts the disillusion and falling-out of three seemingly close friends only the action takes place in reverse so we start in 1980 with Frank, Charlie and Mary no longer speaking, through all the compromises and betrayals that erodes their friendship to the final scene which shows them all meeting for the first time on a NY rooftop to watch Sputnik overhead in 1957. The device is hugely affecting, by the time you reach the end you feel for the three young people, so wide-eyed with hope and optimism for the future which you know will founder on the rocks of distrust, infidelity, compromise and alcohol.

I was curious to know exactly how they were going to stage this - surely they couldn't just sing the songs with maybe an onstage narrator filling in the blanks? Luckily no, we got the full show acted out although with no costumes and in between lecterns set up across the stage. I was worried that Owen, who had not seen the show, would not be able to get into the story but luckily the performances more than made up for any lack of trappings. Reprising their roles as Mary, Charlie and Franklin were Samantha Spiro, Daniel Evans and Julian Ovenden and it was a delight to see them together again, they obviously enjoy each other's company as much as we did! All three were in fine voice and transcended the bare stage and their fellow cast members sitting in a semi-circle at the back of the stage to flesh out their characters and their stories.

Also I should mention the scene-stealing Anna Francolini as Gussie, I had quite forgotten what an excellent character the book writer George Furth created in her - the bitchy, egomaniacal Broadway star who becomes Frank's second wife. Fine support too was provided by Mary Stockley as Beth, Frank's first wife and James Millard as the crass but caring Broadway producer Joe Josephson.

And of course it was a joy to hear Sondheim's blissful score 'live' again - with songs of the calibre of "Not A Day Goes By", "Good Thing Going" and "Our Time" it is truly one of his most under-rated scores. I don't mind telling you I was a-blub for most of the second half.

Unbelievably there are still people who purport to love the theatre who still fail to recognise Sondheim's unique place within it - surely anyone who has been able to experience in the space of the last few months his individual scores for ASSASSINS, PASSION, INTO THE WOODS and now MERRILY must surely be able to understand exactly why he is to be celebrated as he has this year.

This Sunday sees a similar concert performance of COMPANY with the cast of the Donmar's 1995 production - I cannot wait!