This series focuses on the history of the organs in the School Chapel, from the first one installed in 1930 to the current instruments built in 1993.

This series focusses on the headmastership of Grosvenor Talbot Griffith (1935-1958) and contains items relating to the life at School in the mid-20th century, its staff and pupils.

This series focusses on the headmastership of John David Buchanan (1958-1977) and contains items relating to the life at School in the 1960s and 1970s, its staff and pupils. The bulk of the series consists of books, publications, letters, speeches and sermons written by Mr Buchanan himself.

This series focusses on the headmastership of Oliver Richard Sylvester Bull (1977-1984) and contains items relating to the life at School in the 1970s and 1980s, its staff and pupils. One of the files relates to Michael Stevens as Acting Headmaster for two terms in 1985.

This sub-series focuses on the history of the 1993 Organ in the School Chapel. After the 1930 organ expired and was replaced by a computer organ in the 1980s, the headmaster Graham Smallbone commissioned for a new organ to be built. Some items highlight the various proposals, the correspondence focuses on the building and installation of the organ and the photographic file finally shows the organ in Chapel.

This file focuses on the correspondence between Oakham School and organ builders, including Peter Collins Ltd, since 1990 and giving an insight as to the building and installation of the new organ in the School Chapel. Some letters were sent/ received between the Headmaster Graham Smallbone and the White and Lea families regarding an inscription in memory of David White and Henrietta Lea.

A letter from the Headmaster Graham Smallbone to Liz and Chester White replying to the letter CHA/5/2/2/12 and regarding the building of the organ and finding a way to commemorate their son David.

A letter from the Headmaster Graham Smallbone to Liz and Chester White regretting not being able to attend the unveiling of the stained glass window in memory of David White in St John's College School and giving some information about the new organ. This letter is in reply to the invitation CHA/5/2/2/15.

A letter from the Headmaster Graham Smallbone to peter Collins, Organ builder, regarding the carvings, which are a gift from the Whites, and the open day and the Derbyshire Organist Association.

A letter from the Headmaster Graham Smallbone to Liz and Chester White regarding the installation of the new organ and discussing an inscription that could be made to honour David White and Henrietta Lea.