There was at first much common ground between Schumann and Liszt. They were on good terms with one another while Brahms was still a toddler. They both counted Beethoven as a prime influence. Both produced orchestral pieces that were symphonic yet composed in one long span, following an extra-musical programme. Both were inspired by literature: it's all but impossible to explore Schumann without reference to authors such as Goethe, Heine, E. T. A. Hoffmann and Jean Paul. 

So one might have expected Schumann — given a longer life, perhaps — to be part of the experimental, referential, exploratory, Lisztian side. Yet his mental illness and the appalling social stigma attached to that condition have skewed the perception of his work, mainly thanks to the attitude of his wife. Yes, that supposed romantic heroine, his beloved Clara. 

This is particularly relevant to his late works. For years, it was thought, principally by Clara and her violinist friend Joseph Joachim, that Schumann's deteriorating mental health caused a parallel deterioration in his music (in some circles it still is). But what if they were wrong? True, the late works can sound rather odd — but supposing they demonstrate not mental weakness, but a new creative direction? 

Take the much-maligned Violin Concerto, which Clara and Joachim suppressed and which consequently lay buried in a Berlin library until 1933. Could it be that the wandering solo line in the slow movement is in fact perfectly sane? It's a sort of stream of consciousness that plays around the imagined theme rather than through it, lending the piece an ethereal and elusive beauty. And what if the late piano pieces Gesänge der Frühe are not sketchy fragments but new musical thinking with ideas refined down to the bone? 

Clara remained the gatekeeper of her husband's work until her death in 1896, 40 years after his. Having been aware of his unstable behaviour from the beginning — it was a prime cause of her father's objections to their marriage — it's possible that she was terrified of any diversion from the conventional, pure and sane in Schumann's work, lest it prove that his mind was wandering in dangerous, deranged directions. She always encouraged him away from experimental or obscure writing towards a more traditional, commercial and publicly effective approach. 

This may also be one reason Brahms veered towards his own highly structured, supposedly "pure" approach: experimentation, "obscurity" and unconventionality, to Clara, may have been associated with madness, and perhaps to him, too, thanks to his formative friendship with Clara. 

Eric Frederick Jensen's study in the  Musical Times in 1998, "Buried Alive", suggested that Schumann was well enough to come home from Endenich, but that Clara, for whatever reason, chose to leave him there. His death may have been the result of a hunger strike in protest over his appalling treatment. 

The arguments go on. Schumann's bicentenary should be offering a chance for a serious reassessment of all the evidence. I hope there's still time for it to do so.