T.C. Lewis 1897, Willis III 1952, Harrison & Harrison 1991

The Cathedral's organ was built by Lewis & Co. of Ferndale Road, Brixton, south London, and completed in 1897. Thomas Christopher Lewis, the company's founder, was renowned for building instruments that had a bright, vibrant tone which, in part, was due to his use of low wind pressures. Consequently, he was somewhat out-of-step with the trend at the time, which was tending towards high wind pressures and rather thicker tone. The instrument's action was, and is, electro-pneumatic with slider chests, and the main case was designed by the noted Victorian architect Arthur Blomfield.

Apart from routine maintenance, the instrument remained untouched until 1952, when Henry Willis & Son undertook a major rebuild, during which the wind pressures were increased. The balanced Swell pedal and the hitch-down Solo pedal were replaced by Willis's Infinite Speed and Gradation pedals. The Choir organ - which had been housed in front of the Swell - was relocated to the north side and a new console was installed adjacent to it (the original console was on the south side). The Choir organ's Flauto Traverso was replaced by a Nazard, and a Tierce was provided on a new slider. A number of new couplers were also provided and the Violon unit (32'-16'-8') was extended by 12 pipes to create a Viola 4'.

Some years after the rebuild it was thought that the Willis changes, though undoubtedly well-intentioned, detracted too much from the original concept, so the decision was taken to restore the instrument to the Lewis specifications. The Durham-based firm of Harrison and Harrison was engaged and the work was carried out in two stages. Firstly, in 1986, the electrics were renewed and although the Willis console was retained, it was given a solid state action with eight memory levels for the combination pistons and four for the Crescendo pedal. Also, the Willis swell pedals were replaced by balanced pedals. In 1991, the main work was undertaken, including the re-voicing of the stops on Lewis's original wind pressures. A Lewis Flauto Traverso rank was obtained for the Choir organ, to replace the one discarded by Willis, and the Nazard and Tierce were removed - meaning that the Great organ's Octave Quint is now the instrument's only mutation register. The two prepared for drawstops on the Pedal were also disposed of. Thus, the stop list is now as Lewis left it, except for the Viola 4' which was retained because it was a gift in memoriam.