Arguably the most distinguished European organ builder of the 19th century, the Frenchman Aristide Cavaillé-Coll (1811-1899) pioneered innovations in the art and science of organ building that permeated throughout the profession and influenced the course of organ building through the early twentieth century, and in the last few decades of the nineteenth century Cavaillé-Coll's designs were extremely fashionable. He was the author of many scientific journal articles and books on the organ in which he published the results of his researches and experiments. He was also the inventor of several organ stops such as the flûte harmonique. Cavaillé-Coll was responsible for many innovations that revolutionised organ building, performance and composition. He placed the Grand-Chœur (great, or literally “great-chorus”) manual as the lowest manual, and included couplers that allowed the entire tonal resources of the organ to be played from this manual. He refined the English swell box by devising a spring-loaded (balanced) pedal with which the organist could operate the swell shutters, thus increasing the organ's potential for expression. He experimented with pipemaking and voicing techniques, creating a whole family of stops imitating orchestral instruments such as the bassoon, the oboe and the English horn. His harmonic flute stop, together with the montre, the gambe and the bourdon, formed the fonds (foundations) of the organ. He introduced divided windchests which were controlled by ventil shutters and allowed the use of higher wind pressures and he devised a mechanism for each manual's anches (reed stops) to be added or subtracted as a group by means of a pedal. Higher wind pressures allowed the organ to include many more stops of 8' (unison) pitch in every division, so complete fonds as well as reed choruses could be placed in every division, designed to be superimposed on top of one another. On occasions he placed the treble part of the pitch spectrum on a higher air pressure than the bass, to emphasize melody lines and counteract the natural tendency of smaller pipes (especially reeds) to be softer.
The organ “symphonies” of French composers such as Vierne and Widor were substantial works of five, six, and even seven movements. They were given the title of symphony, rather than organ sonata (which is in fact what they are), because during the nineteenth century, and at the hands of builders such as Cavaillé-Coll, the organ developed into a much larger and more expressive instrument than that which the baroque and classical composers had had at their disposal. The organ was now being built on a scale which rivalled and competed with a romantic symphony orchestra of 90+ players, and new romantic stops, especially reeds, were developed to imitate the power and grandeur of an orchestra. Some of these stops even had orchestral sounding names (clarinet, trombone, trumpet, contrabassoon, tuba). Composers such as Liszt, Mendelssohn, Brahms, Bruckner and Reger were writing works for organs, on a vast symphonic scale; works which made great demands on both instrument and performer. The organs of Cavaillé-Coll, although restored, can still be heard today in recordings of Vierne's music and that of other French and German romantic and modern organ composers. Whilst the organs have undergone technical improvement, modernisation and renovation, the pipework, that which actually produces the sound, is unchanged. Whilst it could be said that these instruments lack the tonal clarity of the earlier Baroque organs, created to bring out the various simultaneous melody lines in contrapuntal music such as the trio sonatas and fugues of J. S. Bach, the sounds of the pipes in a Cavaillé-Coll organ blend together tonally in the way that the different timbres of the instruments in a symphony orchestra do; their powerful reeds, created to stir the emotions, do so in the same way as a symphony orchestra playing flat out. The organ which Vierne had at Notre Dame, and on which much of his organ music would have received its first performance, was a huge contemporary example of a Cavaillé-Coll. The organs at Ste Sulpice and Ste Clotilde were also vast instruments built by Cavaillé-Coll. Both of the Messe Solenelles in this evening’s concert were written to exploit the immense resources and tonal capabilities of these organs.
The current organ in St Machar’s Cathedral was built by the Henry Willis company of London. Willis, a direct contemporary of Aristide Cavaillé-Coll, and known as “Father Willis” because of his huge contribution to the art and science of organ building, and to distinguish him from future generations, was the leading organ builder of the Victorian period and contributed a fine four manual organ to the Great Exhibition of 1851. This instrument won a gold medal and was later moved from the Crystal Palace and installed in Winchester Cathedral, where it is still in daily use. Other prominent “Romantic” Willis organs still in regular use are to be found in St Paul’s Cathedral, as well as the cathedrals of Gloucester, Lincoln, Salisbury, Durham, Canterbury, Glasgow, Edinburgh (St Mary’s), Liverpool, Westminster, Hereford and Truro. During the Industrial Revolution, a time when both civic and religious commitment led to the erection of a number of impressive buildings and many towns equipped themselves with imposing town halls, often installing a Willis organ. The largest organ in the world at the time, with 111 stops, was the Willis organ installed in the Royal Albert Hall in 1871. It too is still in use. Other prominent locations of Willis organs are Blenheim Palace, the Sheldonian Theatre in Oxford and the Royal Academy of Music. One in Windsor Castle was destroyed in the fire of 1992.