The two manual organ by Harrison & Harrison, Durham was installed in St John’s in 1971. The pipework is housed in the gallery with free-standing console situated downstairs beside the chapel. The organ boasts a Trumpet en chamade on the Great organ.
The organ specification:
| Swell Organ (enclosed) | Great Organ | Pedal Organ |
|---|---|---|
| Tremulant | Tremulant | Trumpet 8’ |
| Trompette 8’ | Trumpet 8’ (en chamade) | Posaune 16’ |
| Dulzian 16’ | Sesquialtera II | Mixture II |
| Cymbel III | Scharf II | Nachthorn 4’ |
| Larigot 11/3 | Mixture IV-V | Gedackt 8’ |
| Gemshorn 2’ | Super Octave 2’ | Principal 8’ |
| Koppel Flute 4’ | Octave 4’ | Gedackt Pommer 16’ |
| Spitz Principal 4’ | Rohr Flute 8’ | Swell-Pedal |
| Gedackt 8’ | Principal 8’ | Swell Octave-Pedal |
| Salicional 8’ | Swell-Great | Great-Pedal |
| Octave | Swell Octave-Great | 6 Swell Combination Pistons |
| Sub Octave | Swell Sub-Great | 5 Pedal Combination Pistons |
| Unison Off | Great+Pedal Combs coupler | Pedal cancel Gt-Ped |