The organ is, like the great building which houses it, a masterpiece and one of the most important instruments of its period. Built by the firm of William Hill & Sons Ltd, the first portion of the instrument was erected in the building in 1894. Following the completion of the east end, the full scheme was realised and the organ placed in a specially-designed chamber above the north side of the chancel in 1905. The spectacular organ cases were installed in 1915. Designed by Frank Loughborough Pearson (son of the church's architect), they are justly internationally famous for their beauty. The instrument itself is one of the largest church organs of its time and as an 'untouched' example of the Hill style, has informed the restoration of several other historic Hill organs, including those of Peterborough and Lichfield cathedrals, as well as that of Eton College.