On Sunday 3 March, the music world lost the British organist Peter Hurford, who died at the age of 88. Best known for his recordings of Bach, he was prolific in the recording studio with over fifty albums to his name. Decca was his primary label and his discography includes a fine rendition of the Handel organ concertos, Op 7 made with the Concertgebouw Chamber Orchestra and Joshua Rifkin (“Hurford’s playing is regular and vigorous, matching the full-blooded pounce of Rifkin’s direction, all as fresh as a new-laid egg” – Gramophone, 1986). Hurford’s death is unfortunately timed with this month’s Eloquence re-issue of his splendid recital at the Sydney Opera House in 1982. Writing the following year, Gramophone wrote “This is the sort of programme with which organs are baptized … There is a springiness in the playing which comes up fresh every time … All very good value.”

The grand organ of the Sydney Opera House is believed to be the world’s largest mechanical-action organ. It is housed in the Concert Hall, the largest of the Sydney Opera House’s theatres, and was built by Ronald Sharpe, who was assisted by a small personal staff and, during the final phase of construction, by the Austrian organ-building firm of Gregor Hradetzky. Its construction began in May 1969 but the planning and design had begun several years earlier. Completed in May 1979 at a cost of $1.2 million, it is only recently that the Sydney Opera House organ has come to be regarded as one of the finest instruments in the world.

Its construction parallels that of Sydney’s other great concert hall organ nearly a century earlier, the William Smith & Sons instrument in the Sydney Town Hall. That organ, and indeed the Centennial Hall (as Sydney Town Hall was then known), was also of record-breaking size and the organ itself is still widely regarded as one of the finest examples of its kind from the nineteenth century.

The Sydney Opera House organ, however, is unique in that it has married the materials and fine craftsmanship of traditional organ-building with modern materials and technology to create a magnum opus for the twentieth century. The result is a creation, very much like the work of art in which it is housed, that has attracted international respect and stirred national pride.

The visible portion of the organ is an imposing fifteen-metre façade consisting of 109 show pipes, made from pure tin and polished to a glittering finish. Behind this façade is the greater part of the instrument which measures 15m high, 13m wide, 8m deep and weighs in at 37 tonnes. It is built into a shell-like concrete chamber above the stage of the Concert Hall. It is constructed from 10,000 pipes each grouped according to 200 ranks and sub-grouped into 127 speaking stops along with 28 couplers and numerous other percussion and ancillary stops as well as a number of electronic accessories. There are five manual keyboards consisting of 61 keys each and a pedalboard of 32 keys. There are 25 soundboards distributed throughout the framework which support and control the pipes in addition to the air reservoirs, trunking and other mechanisms.

One of the features of the organ is its use of a direct mechanical linkage, known as a ‘tracker action’, to interconnect between the console keys and the pallet valves in the chests that supply air to the pipes. This is the type of action that has been used by classical organ builders before the advent of pneumatic or electric techniques. It has the benefit of giving the player continuous control over pipe speech and makes possible the fullest musical expression of the instrument.

The adoption of this type of mechanism can result in a slightly heavier touch which would usually require the player to apply maximum physical effort to take full advantage of the potential in an instrument of this size. However, this has been minimised by the use of modern materials and particularly through precision design and workmanship.

The way in which electronics have been employed in the design and construction of the organ has also made the instrument unique. One particularly important feature is the way in which the changing of stops and the combinations of stops are used. Whereas organ stops are often fixed by the builder or through what is known as a ‘capture action’, which allows the organist to change stops and combinations of stops according to a preset program, the size of the Opera House organ made such an approach unworkable. Setting up the program for the stop combinations in the Opera House organ, which has 69 pistons, could take more than an hour.

But Ronald Sharpe, along with Myk Fairhurst, found a way round these problems using modern electronics. The capture action has been implemented through a semiconductor memory which is used to store the stop combinations. These can be transferred to an electronic device so that the transfer of information is achieved in a matter of seconds and the need for tedious manual programming is avoided.

Electronics have also been used to improve aspects such as key touch, through the inclusion of an electric action that runs parallel to the system of mechanical couplers, which has had several benefits. A player’s performance or rehearsal can be recorded electronically and, at a later stage, played back so that the performer can more effectively gauge tonal balance and contrast – from the audience’s perspective. Similarly, this can be applied in a way that allows organists to play a duet with themselves. Other benefits include an electronically implemented crescendo that gives the player greater control over this aspect of the instrument.