By Stephen Stafford
BBC Hampshire & Isle of Wight
Peter Hammond brought the organ back from a state of disrepair
Southampton Guildhall houses one of the world's largest pipe organs which has now been given a new lease of life.
The organ, built by the John Compton Company in 1936, is considered by musicians to be one of the most versatile organs ever built.
It features around 4,000 individual pipes and original electrical workings.
The historic instrument had a make-over prior to it taking the starring role in a classical Christmas concert.
When the Southampton Guildhall is being used as rock or pop concert venue, fans are probably completely unaware of the two large boxes either side of the Guildhall stage usually wrapped in black protective padding.
The organist has an entire orchestra at their fingertips
But under the wrapping is a unique musical instrument which would have played the pop music of the day when the Guildhall was built in the 1930s - in fact the organ's workings are so large, the architectural plans for the building were actually drawn up to accommodate it.
The sound of the Compton organ is as evocative of the 1930s as the art deco surroundings of the Guildhall itself.
It was originally commissioned to cater for a wide range of functions including tea dances, variety shows, classical and choral concerts and civil ceremonies.
Therefore, it was built with two keyboard consoles and as such is unique in the world. One is a 'classical' organ, akin to a church organ and the other is a 'theatre' organ.
The two share the same set of pipes and electrical workings, but the latter has, literally, more bells and whistles.
The pipes extend high into the roof of Southampton Guildhall
Despite being a piece of musical history, the organ had fallen into disrepair by the 1990s.
A full refurbishment would have cost around £500,000 so the council brought in organ expert Peter Hammond from HWS Associates to take on the task of repairing or remedying individual problems and faults with the organ mechanisms.
The HWS team managed to resurrect the organ within a much smaller budget and whilst not being a full restoration, so far their efforts have achieved good results.
They have also tuned the instrument thoroughly and succeeded in keeping most of the original workings, electrics and engineering in place as "most of the instrument was essentially sound."
It is only by climbing high above the Guildhall's stage that it is possible to realise the amazing industrial scale of this single musical instrument.
Four cavernous chambers house the workings of the organ. At first the chambers look like the air conditioning or heating system for a small industrial plant, but in reality they hold 1930s technology which is still making music into the 21st century.
Four thousand pipes sing out notes through ornate metal grates above the stage as shutters, controlled by the organist's feet, open and close to alter the overall volume level.
The pipes range in size from around one centimetre in length to 14m high and weighing close to half a tonne.
The original 1930s electrics are still in full working order
The organist has the full range of orchestral sounds at his fingertips - from oboes and clarinet effects (with special reeds built into the pipes) to violins and more standard organ sounds.
The pipes, made of tin and lead and as pliable as a soft drinks cans, extend up into the chambers where the wind is provided by generator and blowers - again powered by 1930s engineering which is still in good working order.
The electrics still largely work, with cotton-covered cables and thousands of switches, relays and contacts for each note, key, effect and stop.
Compton organs were at the cutting edge of technology in an era before electronics and digital computer-based controls.
Remarkably, it has the ability to store organ sound combination settings in electrical memory. A Melotone was designed to emit an electrical tone generated by two spinning discs, long before synthensisers revolutionised music-making.
Organ-building in Europe goes back 1,000 years, but by the 1920s and 30s, theatre organs (and the equivalent Wurlitzers in the USA) were originally built to accompany silent movies in huge cinemas where an orchestra was too expensive and a piano would not fill the hall.
The "fantastically unique instrument" has 4,000 individual pipes
John Compton was the leading British theatre organ-builder (as well as being a prolific church and concert organ builder) of the time whose organs included sound effects - drums, claxons, bird song, trumpets - which an expert organist could play in time to car chases or other dramatic action on the silver screen.
The best theatre organists achieved celebrity status in their day in cinemas, theatres and ballrooms around the country - the music kept its popularity well after the original purpose of accompanying silent movies ended.
After World War II, tastes in entertainment changed and the rock n'roll generation wanted more than sedate 1930s organ music.
However, 70 years after its installation, crowds of music lovers and organ afficianadoes are still drawn to what Peter Hammond calls a "Magnificent and fantasticly unique instrument".