Emotions were running high right from the start of this breathtaking performance, Codebreaker, about the life of genius Alan Turing.

For starters it was the first time composer James McCarthy would see the work, which took him 18 months to create, performed on stage.

Secondly actor Benedict Cumberbatch, who is starring as the World War II hero in upcoming film The Imitation Game, was in the audience at the Barbican Centre.

And thirdly, and most importantly, a show celebrating the brilliant but tragic life of this extraordinary man was long, long overdue.

For those unfamiliar, the evening wisely opened with an informal talk by James McCarthy, Hertfordshire Chorus conductor David Temple and James Grime an expert on the life of Turing, explaining how the genius cracked impossible German codes and was the father of computer science, but was prosecuted for being gay, chemically castrated and two years later, aged just 41 years, committed suicide, leaving no note.

In fact he left behind very little and so McCarthy had to imagine much of the man behind the myth, making Codebreaker a deeply personal composition.

The musical part of the evening started with performances by the Chorus and London Orchestra da Camera of Mendelssohn Hebrides Overture, Fingal's Cave, Vaughan Williams Toward the Unknown Region and Beethoven Meeresstille und glückliche Fahrt, showcasing their skills.

Codebreaker began with the singing of Gordon Brown's 2009 apology on behalf of the British government with the poignant line "You deserved so much better."

Tears were already mounting but were staved off as the piece moved into the joyful telling of Alan's teenage love for Christopher Morcom, drawing on the poetry of Wilfred Owen's Song of Songs and Sara Teasdale's Deep in the Night and Enough with the glorious line "It is enough for me by day, to walk the same bright earth with him" sung in tender voices by the Chorus.

Naomi Harvey's mournful soprano acted as the voice of Turing's mother throughout, singing about Christopher dying suddenly at 18 leaving Alan heartbroken.

Chamberlain's famous speech was then played to herald the start of war, with the percussion and the brass sections were used to great affect in this section, capturing the chaos and tension of war.

The choice of Oscar Wilde's De Profundis was perfect to depict the sorrow of the dreadful fate that then befell Alan and for me the most moving section of the evening both musically and lyrically "To deny one's own experiences is to put a lie into the lips of one's own life."

Edward Thomas' Lights Out marked Alan's suicide followed by Robert Burns' A Mothers Lament for her Child.

James had spoken beforehand of finding it too awful to leave Alan in the grave and so he drew the story to an end with the Chorus' voices rising to a crescendo usingthe words of Sarah Teasdale's If Death is Kind, symbolising Alan reuniting with Christopher and leaving us with the line "the dead are free" echoing in our heads and tears on our cheeks.

Find out more about Alan Turing and codebreaker here

St Albans & Harpenden Review:

Still of Benedict Cumberbatch as Alan Turing in The Imitation Game