Ralph Downes CBE KSG (1904 – 1993), the organist, organ designer, teacher and musical director, greatly appreciated the Mustel harmonium. The extract below is from his book Baroque Tricks published by Positif Press, Oxford. The Mustel mentioned, which Ralph Downes subsequently owned, has now been fully restored.

“The next event was the purchase, by the Oratory, of a superb Mustel organ, on my recommendation, to replace a small accompanimental organ by the Positive Organ Company (Casson) used for certain services sung by the clergy alone around the Feast of Corpus Christi. The Positive was no longer satisfactory: the Mustel was put on castors so as to be mobile and could be wheeled into the Sanctuary as needed. It will be remembered from the Derby cinema-theatre days that the Mustel had quite remarkable power, and was thus adequate in such a large church; also that I was an expert performer on this complicated instrument. This was a fine vintage model, with two manuals, so that most foundation stops ran right through the compass; the broad-toned ones [Bourdon-Clarinette 16, Cor anglais-Flute 8, Voix celeste 8 on the front soundboard controlled by the lower manual; the ‘fierce’-toned reeds (Baryton 32, Basson 16, Hautbois 8, Clairon-Fifre 4, Harpe Aeolienne 8 played by the upper manual; there was a coupler, two sets of swell-louvres for the ‘back’ reeds, and of course the all-important ‘Expression’ stop — whereby one blows with the feet directly into the reeds without using the reservoir, thus commanding a dynamic range from ppp to fff — in addition to the Mustel ‘Double-expression’ which enabled solo stops to be used without fear of being drowned by the accompaniment from the other reeds. This was all remarkable enough, but as heard in the Oratory acoustics, in such works as the 24 Pieces ‘en style libre’ by Louis Vierne, the French aura was quite overwhelmingly beautiful to the ears of one accustomed to play these pieces on typical English stops: this again was a great break-through of ‘the authentic voice’.”