The first organ at St Peter’s Cathedral was built in 1876 by Bishop & Son and contained 29 stops over three manuals and pedals. This instrument was relocated in 1931 to St Augustine’s Church, Unley.

The present four-manual organ dating from 1929 was built in England and Australia by William Hill & Son and Norman & Beard. The 32ft Double Open Diapason pipes were made in Australia and to this day are the largest organ pipes in South Australia. It was dedicated on Sunday 6 July 1930.

The organ has 53 stops and 3,425 pipes. The tallest pipe is over 10 metres tall and the smallest is just 2-3 cms tall with the diameter of a pencil.

In 2017/18 the organ was restored and rebuilt by Harrison and Harrison of Durham at a cost of $1.6 million. The organ was rededicated on Sunday 2 December 2018.

As part of the restoration, while safeguarding the romantic style and character of the 1929 instrument, it was possible to install modern playing aids to allow the Cathedral musicians to have an instrument fit for today’s liturgical requirements, as well as for concerts that are held regularly here. The instrument is one of the grandest and substantially unaltered organs in Australia, making it one of significant importance.

W wooden case was designed by Cathedral Architect Walter Bagot at the time of installation of the organ, but was not completed through want of funds. The first part of the wooden case work was donated in 1963 by Walter Bagot, and was constructed by A. S. Bissland. It bears the arms of “Bagot of Blythefield,” from which illustrious family the late Walter Bagot was descended. The upper part of the case was realised using the original 1929 Bagot sketch, modern design tools and laser-cutting technology to complete the design economically.

The console comprising the 4 keyboards for the hands and a separate, shorter keyboard for the feet is located in a raised loft behind and above the Choir Stalls on the pulpit side. It is concealed by a curtain. The organist watches the choir conductor via a CCTV camera and monitor, and a strategically placed and angled mirror.

There are a number of young people who are learning to play the organ, and the Cathedral also has a scheme for appointing and training an organ scholar, thus assuring the ongoing use of this magnificent instrument.