Although it seems surprising that Beethoven agreed to this compromise the artistic reason for it could have been deeper than a mere desire to please, or a lack of confidence in his own judgment. Such indecisions had plagued him before, in the Fifth and Ninth Symphonies, in Fidelio, or in the appalling cuts and shifts he suggested in the 'Hammerklavier' Sonata. Publishing the Grosse Fuge separately as Op 133 may well have been done in the hope that it would eventually find its way back to its original place, as it now often does, for it is widely and rightly felt that the small 'Substitute' finale cannot counterweigh the great first movement. But if the Grosse Fuge is restored to Op 130, what are we to do with the other piece? The idea that two such disparate movements are satisfying alternatives could be sustained only by ingenuity. Perhaps the answer lies further back.
Listening to the first movement, notice the mysteriously disembodied effect of the whole second group in the strange key of G flat, approached abruptly, and not grounded as a tonality at all. The same thing happens in the Grosse Fuge, even more mysteriously, when everything slips into a wonderful animated cloud of soft G flat. These two events are crucial. The work as a whole also has something in common with a Bach partita; Beethoven in his later works searches the past ever more deeply.
The first movement is followed by a very fast and short Scherzo in the tonic minor; the next movement ambling gently and delicately, with many original quartet textures, is in the related key of D flat. Then comes the simple 'Alla danza tedesca', but suddenly in the strange key of G major, as far away as possible from D flat — a switch to the other side of the musical universe! This violent dissociation, expressed in the simplest language, is the secret heart of the work, psychologically connected with those in the first movement and the Grosse Fuge.
From G it is an easy step to E flat, where we find the touching Cavatina, and the note G at the top of its last chord begins both the Grosse Fuge and the second finale. The Fugue is a mighty struggle stretching mind and sinews to the limit, and besides the great G flat dissociation it contains, it also makes another such rift by means of the key of A flat, the 'contradictory' flat seventh of the tonic B flat. But at length, with an unmistakable sense of release, it breaks through into sunlight — the air is all at once fresh and free, and the music takes flight. Does not the extra movement say, gloriously, 'Now we can play!'? Is it not a felicitous appendix, in its vivid delight the most heroic of all Beethoven's utterances?
His bodily condition was piteous, but his spirit found its way into this sparkling Allegro in which all tonal contradictions and dissociations are wonderfully resolved (especially the A flat question, the point of which depends on our having heard the Grosse Fuge). There is a powerful case for freeing ourselves from the vexing choice. Beethoven might have welcomed this way out; perhaps he felt that Op 130/133 was somehow not quite finished. Therefore, already in extremis, without time to change existing publishing arrangements, he achieved his happiest music. Shouldn't it take its natural place?
from notes by Robert Simpson © 1991