The chapel of King’s College, Cambridge, is known around the world, in the words of David Briggs, who narrates this film, ‘for its history, its architecture and its music’. Specifically, the music that King’s is known for is its choir of boys and men, which achieves annual international exposure with the Festival of Nine Lessons and Carols. Visitors to the chapel marvel at the golden organ pipes that adorn the central screen, and viewers of the chapel’s annual broadcast of Christmas carols are well used to the obligatory shot of a be-cassocked organ scholar working his way through the introduction to a hymn or carol at the organ’s console. But for most, the organ is simply a part of the fabric of the chapel, an essential but often unnoticed support to the choir, and something that usually gets taken for granted by all except a tiny handful of organ aficionados.

Until, that is, it isn’t there. And it wasn’t there for much of 2016 when, after 82 years of tireless service, it was taken away, lock, stock and barrel (or, more specifically, pipes, windchests and stop-jambs) to Harrison & Harrison’s factory for a complete rebuild.

This film follows the instrument’s journey from dismantling to reinstallation, involving a 400-mile round trip for all its constituent parts – including over 4500 pipes – between Cambridge and Durham. The mind-boggling logistics of the operation, the complexity of the process and the amazing skills involved – ranging from computer technicians and wiring specialists to sheet metal workers and carpenters, not forgetting voicers, tuners and wind-supply checkers – are all vividly conveyed. And all against a ticking clock which, as stressed by Stephen Cleobury, the director of music who had set the whole operation in chain, was to ensure that the Festival of Nine Lessons and Carols did not go ahead without the chapel’s organ in full working order. Another part of the narrative thread that turned this film from documentary to, at times, almost gripping story was the unexpected discovery of asbestos in the wind supply of the old organ.

There is touching human interest, too. Through finding scrawled hieroglyphics on some of the original organ pipes and in archive records, Geoff Pollard, one of the builders involved in the project, could trace his family’s involvement with the King’s organ: both his great uncle and his grandfather had been involved in the 1934 build of the instrument; and more than that, he could trace his organ-building ancestry through his own father right back to his great-great-grandfather. Indeed, one of the delights of this film is the team of Harrison & Harrison builders who, to a man, revealed a love and enthusiasm for their work that seemed all the more sincere when voiced through very un-Cambridge accents.

A short and illuminating diversion into the world of organ pipe acoustics is provided by a professor of musical acoustics, a keyboard specialist comes up with a neat solution for dealing with worn-out ivory keys, while 3D graphics and some aerial shots inside the chapel provide a fascinating view of the mechanics of organ design and construction. Hidden detail (including some 60,000 metres of wiring between console and computer control box) is laid bare to the cameras as the organ is gradually taken down to leave just ‘a skeleton of carved oak’ remaining on the organ screen.

Briggs is a clear and knowledgeable guide, putting both his intimate understanding of the instrument and his improvisatory skills to good use in displaying some of its more unusual features. His demonstration of the new ‘Pedal Divide’ device is pure musical magic. An unbroken alternation between a recording made inside the organ and outside in the body of the chapel also provides a potent demonstration of the comment that ‘one of the finest stops on the organ is the acoustic of King’s College Chapel’.

Fugue State Films is the market leader in the somewhat niche field of organ-centric DVDs, and this is another major project brilliantly executed by cameraman and director Steven Benson and producer Will Fraser. But over and above the exceptional quality of the filming, the editing and the overall production, there is far more here than the story of a famous organ being rebuilt. That takes up just one DVD. There is a second DVD of performances on the rebuilt organ by seven of King’s former organ scholars, including Briggs himself, which are also presented on two audio CDs of outstanding sound quality, and a booklet detailing the full specification of the newly rebuilt organ. All in all, this is not only a fascinating historical record but also a superlative musical one.