I am not sure if trying to answer the question, of who are the greatest organ music composers, is not akin to putting ones head in the lions mouth. Such is the influence of personal taste, period and style perhaps the question is almost a silly one to pose?
Even so I think there will be universally agreed ‘giants’ of the instrument whose music is adored by a wide audience.
Is J S Bach the king of organ composition?
It is certainly true that very many organists will consider J S Bach as the absolute king. His output was prodigious and the extraordinary mastery of melody line harmony and structure is breath-taking.
There is either a great comfort the listener will gain from the mathematically logical and reassuring shape Bach gives to his work or it will irritate by the consequent predictability of its direction. Whatever you think on that point it is brilliantly inventive and a world without Bach for an organist is almost inconceivable.
Charles Marie Widor a genius of a different kind
Moving on a couple of hundred years I think I am on safe ground to put Charles Marie Widor firmly on the list. Here is genius of quite a different kind no doubt in part driven by the very different instruments at his disposal.
Cavaille-Coll, arguably the worlds best organ builder offered Widor instruments of enormous scale which allowed a symphonic style of composition. Here structure does not dominate as Widor exploits an abundance of texture and sounds to entertain us with music also arguably more technically demanding to deliver. His monumental series of Symphonies are works of great complexity with some truly amazing movements. Perhaps not all are of astounding quality but it is only because the great movements are so unbelievably great that others by comparison disappoint.
The complete series of Symphonies has been brilliantly recorded by Joseph Nolan on the Signum label to very high acclaim. These recordings will confirm all that I say above.
Julius Reubke and Olivier Messiaen
Who next on this list? The choices get harder. It is difficult now not to allow composers for whom individual pieces are so well known and respected that they are held high for what are rather individual moments of glory.
Julias Reubke who died tragically early is a case in point. I have no doubt that had this mans output been greater he would be remembered for far more than his Sonata on the 94th psalm. Reubke manages to write in a style that is so so difficult technically to play on the organ that it near defies logic. Yet he creates a work of amazing emotional intensity that stands as high as any other I can think of.
Moving to more recent times it would be wrong not to refer to the great French composer Olivier Messiaen. Organist at La Trinite Paris for over 60 years. I am not a great personal fan of the works of Messiaen but his writing that often mimics bird song with use of the many colours of the great French instruments had certainly received high acclaim much down to the performances given by his star pupil Dame Gillian Weir.
A personal favourite by Maurice Duruflé
A personal favourite for me is the Prelude and Fugue on the name of Alain by Duruflé. Jean Alain, brother of organist Marie Claire Alain, was a composer killed in the war in 1940 aged just 29. This tribute by Maurice Duruflé with a short but haunting repeated melodic theme is ethereal and inspired and one senses the respect and sense of loss Duruflé must have had for his friend Alain.
Duruflé of course wrote many other great works but none quite have the same emotional impact for me as this work finishing as it does with a rage symbolic of the pointless loss of a great musical mind. This is inspired writing of the highest order.
There are of course many other great composers and some exceptional pieces of output from others less well known. The range is extensive with the organ drawing as no other instrument does on the building in which it sits.
There are pieces that were no doubt written for a particular instrument and separation of that piece from the building and its instrument can never quite create elsewhere what the composer had in his head at the time he or she put ink to paper. Such is the wonder and challenge of the organ and its repertoire.