With Samson François (1924-70) you face controversy and a conundrum. If opinion outside his native France has always been sharply divided, this division was provoked by the sheer inconsistency of his performances. These ranged from playing that exuded an imaginative freedom and feline facility that others could only dream of, to performances that were chaotic and ill-focused or, perhaps most regrettably, ordinary and lethargic.

In the 1960s I attended three recitals given by François in London’s Royal Festival Hall. The impact of the first two has haunted me ever since. This is an experience I share with the pianist Brigitte Engerer, who wrote of how she left a François recital as reeling and stupefied as she was envious and disturbed. How was it possible to consider herself an artist after hearing playing that somehow transcended, indeed soared far above all tenaciously held notions of ‘correctness’, training and convention? Suddenly everything she had been taught seemed irrelevant, even risible. I recall a colleague whispering to me ‘more and more daring!’ during a performance of Chopin’s G minor Ballade, as François wove his extraordinary spell. I also recall a Fauré Second Impromptu spun off like so much iridescent thread and an ‘Ondine’ from Ravel’s Gaspard de la nuit of an unforgettably seductive shimmer. Alas, my enchantment was not shared by The Times’s music critic: a short and scratchy review appeared the following day that viewed François’s freedom as wilful caprice and an absence of clarity and responsibility. The third recital was a disaster, a sea of blurs and mishaps, prompting a British pianist to exclaim that ‘it is inconceivable that someone so devoid of musical or technical ability could ever have given a decent recital’.

Moving to the present day we find that two of the most remarkable young French pianists – Alexandre Kantorow and Bertrand Chamayou – can appreciate François without resort to past extremes (on the one hand Alexis Weissenberg considered François to be gifted but irresponsible; on the other, he was for Pierre Barbizet the greatest pianist in the world). Kantorow and Chamayou are enthusiastic but measured, their responses enabled by a certain distance. For Kantorow, hearing François was clearly extraordinary, even chastening: when you prepare for concerts with every possible care and diligence it must have been startling to encounter a pianist who clearly prepared little and relied dangerously on the inspiration of the moment. He describes a live performance of Ravel’s Left-hand Concerto as ‘one of the most incredible things I’ve ever heard’. Chamayou has spoken amusingly and significantly of how, as a student, he was warned by his teachers not to listen to François, whose playing was viewed as a dangerous incentive to eccentricity and risked luring an impressionable young musician down the wrong path. Today Chamayou can hear François fully aware of his inconsistency and is no longer made to feel ashamed of listening to a pianist clearly frowned upon by the more conservative members of the musical establishment. Khatia Buniatishvili, too, has described being lost in wonder at François’s freedom; and we also recall the story of Wilhelm Kempff listening to François playing Chopin’s Polonaise-fantaisie and exclaiming ‘there is no greater performance of this work’.

What do you make of a pianist who would happily taunt and delight the press with outrageous comments: ‘Beethoven’s piano sonatas bore me with their plastic inadequacies’; ‘Mozart enchants me, but why trouble a big piano with a composer of sonatinas?’; ‘don’t mention Brahms, my fingers ache at the mention of him’; or, more specifically, regarding Chopin’s B flat minor Sonata, ‘the funeral march is like sun following the rains’? As François’s son Maxime tells us, his father had a strong sense of occasion and media savvy. In this sense, he shared Arthur Rubinstein’s awareness of the necessity for a public persona (Rubinstein once declared after a successful tour of Spain, ‘I love Spain as one loves a woman, with tenderness’). François delighted in his varying hairstyles, the famous tassel that appeared to rise and fall in time with the music later replaced with a fringe that fell like a silken lampshade practically obscuring his eyes.

If great artists – be they pianists, singers or actors – frequently exhibit a divided self, with François the inner and outer aspects of his nature became inseparable, his flamboyant lifestyle and wildly varying piano-playing mutually interconnected. Lucy Uninsky – the wife of my own piano teacher – once recalled a Paris performance when François appeared with his white tie and tails discordantly offset by a pair of gym shoes; on this occasion the care he gave to his appearance did not extend to his feet. ‘Pauvre Samson,’ exclaimed Cécile Ousset, ‘une problème,’ illustrating his notorious alcoholism with a gesture. François was rarely seen without a glass of whisky in one hand and a cigarette in the other. He preferred the Paris nightclubs to the practice room, passing away the small hours collaborating with fellow lovers of jazz, for him a necessary freedom. By his own admission he lived in his imagination rather than in the more boring alternative of reality, happy to spin legends about his background, indifferent to their veracity. With François there was always a touch of mythomania.

Cortot immediately sensed something exceptional in François, a pianist after his own heart. It was after all Cortot who asked his students to be free, ‘love yourselves, improvise’ his frequent cry. But considering François unteachable, he sent him to Marguerite Long and Yvonne Lefébure, who made little headway against François’s refusal to conform – to have, in his own words, his ‘wings clipped’. At one point Marguerite Long hit him, infuriated by his indifference. François went on to observe: ‘Madame was quite right! I never did anything she told me. And what an honour to be the only student she slapped!’

François had a legion of admirers. For them he could do no wrong, and they swept aside any criticism. Outside France people took a cooler view. Abram Chasins, in Speaking of Pianists, dismissed François, along with other European-based pianists including Annie Fischer, as being nothing special, and certainly no better in any sense than American pianists. A high-handed confrontation with Leonard Bernstein during their Carnegie Hall appearance in Prokofiev’s Fifth Concerto put paid to François’s American career. Offending Bernstein was not a realistic option.

Turning to François’s recordings, we find his legacy predictably unpredictable. He would have scorned any attempt at analysis and viewed criticism as a form of death, the death of the creative and recreative spirit. His recording of both the Ravel concertos with André Cluytens is often considered to be a reference version, and even when compared with the legendary wonders of Michelangeli and most of all Martha Argerich he offers something of such distinctive character that it makes comparisons irrelevant. Everything seems improvised on the spot, a loving tribute to the G major Concerto’s inimitable Gallic nature. As always you sense the elfin in François’s playing, but also a beauty in the central Adagio assai that is inseparable from that peculiarly untranslatable term ‘tendresse’. He captures the malevolence of the Left-hand Concerto with a heart-stopping build-up to the climax of the cadenza.

Chopin was always at the core of François’s repertoire and in the B flat minor Sonata – which he recorded several times, but I’m thinking particularly of the 1955 account – he roars into the development with an elemental force. The Études are a mixed bag like so much else, but in the last three, Op 25 Nos 10-12, he once again thunders Chopin’s violence to the heavens. The Tarantelle, Chopin’s light-hearted tribute to Italy, is a disappointment after the Festival Hall performance I witnessed, where the composer’s Presto marking was transformed into a gently singing and moving Andante that might have made even the composer think again. Such perversity, such waving of a magician’s wand! On record everything feels back to normal and comes as a sad let-down.

The Waltzes, too, are an uneven experience – just when you might have expected François to excel in music where emotion is permitted to suggest itself only through a veil of elaborate civility. The Mazurkas are also a disappointment. You could join those who delight in François’s freedom, in his being as it were untethered from the score, yet they surely emerge as lightweight alternatives to Chopin’s greatest masterpieces, to his Ballades, Scherzos, sonatas, the Barcarolle and the Polonaise-fantaisie. There is too little sense of what I am fond of calling ‘Chopin’s confessional diary’, a repository of his secrets and confidences both dark and light. Despite incidental successes, they ultimately seem superficial alongside Rubinstein’s 1930s recording, where every harmonic and rhythmic piquancy is so miraculously registered within rapidly flowing tempos. There is also little here to match Martha Argerich’s astonishingly fluid and idiosyncratic way with the Op 41 Mazurkas.

Scattered on YouTube you can, again, hear a wild variety of performances. What to make of such a tame and literal opening to the so-called ‘Heroic’ A flat Polonaise, and why so loud and garrulous in the Fantaisie-impromptu’s central episode? You would never guess from François’s listless view of the E minor Concerto that this was a young man’s music, in playing seemingly at one remove from such early ardour. The Ballades and Scherzos leave you at sixes and sevens, admiring the fervour of the ending of the G minor Ballade, if surprised by the flustered way with the dramatic curtain-raiser that leads so audaciously into sudden calm and lyricism. The Fourth Scherzo has its mercurial brilliance erased by an oddly leaden and uncertain approach. You can hear a superb performance of Prokofiev’s Seventh Sonata, with everything in the Precipitato finale gloriously in place despite a ferocious tempo, and then contrast this with another live performance on record that concludes with the musical equivalent of a car crash. There is a thrilling but almost comically chaotic performance of Saint-Saëns’s Toccata from Op 111.

I could go on (François made a vast quantity of records). Here was, and forever is, a pianist who claimed he wanted to be possessed by, rather than possess, music. In the words of Ella Fitzgerald’s song, he left you bewitched (occasionally), bothered (frequently) and bewildered (most of the time). So let me end on a positive note and celebrate what is surely among the most demonic pieces of piano-playing on record, the 1947 performance of Ravel’s ‘Scarbo’ (from Gaspard de la nuit), full of wild approximations, risking everything yet creating a truly terrifying experience, and perhaps making you wonder about a sudden admission that François carried death in his soul, that he knew the knives behind the shadows. Ultimately, Samson François was simply Samson François, a pianist who cared not a jot for anything beyond his simple claim, ‘I play the way I play’.