The organ was built in 1937 by the John Compton Organ Company Ltd and in true Compton fashion, the entire instrument is built on the extension principal using 4 ranks of pipes fully enclosed. At St Begh's, the chamber is located on the rear gallery with the sound directed from out the top. 

The specification reads:

Bourdon 16'
Flute 8'
Salicional 8'
Tromba Bass 16'
Great to Pedal
Swell to Pedal

Contra Salicional 16'
Diapason 8'
Hohl Flute 8'
Salicional 4'
Octave 4'
Salicet 4'
Twelfth 2.2/3'
Fifteenth 2'
Swell to Great 

Hohl Flute 8'
Salicional 8'
Flute 4'
Salicet 4'
Echo Cymbale III
Contra Tromba 16'
Tromba Horn 8'
Octave Tromba 4'
Tremulant (affects all divisions)

4 double touch thumb pistons to Great and Pedal
4 double touch thumb pistons to Swell and Pedal
1 canceller thumb piston - Great to Pedal
1 canceller thumb piston - Swell to Pedal
1 general cancel thumb piston
1 balanced expression pedal - organ
1 balanced expression pedal - crescendo
Double touch canceller to each division
2 ventil switches