This is the first time Alkan has been granted box-set status. It is a remarkable promotion for a composer who sits below the salt despite the advocacy of many distinguished pianists. Perhaps this collection will help alter that for, with all his eccentric, uneven and often bizarre creations, there can be no doubt that Alkan is one of the very greatest and most important writers of music for the keyboard.

If you are encountering his music for the first time, might I suggest beginning with disc 8. This opens with the first Nocturne, Op 22 (1844), its seductively lovely theme never captured better than here by Alan Weiss on one of the earliest recordings in the collection (originally on Fidelio 8839, 1989). That is one side of Alkan. He follows it with the polar opposite, the brief Toccatina, Op 75, one of his last published works, a fiendish ‘quasi prestissimo’ perpetuum mobile. Weiss dispatches it with exuberant aplomb before launching into the three Chants, Op 38a. Alessandro Deljavan takes over for one of Alkan’s most original conceptions, the Trois Grandes études, Op 76: No 1 is among the first significant works for the left hand alone (Fantaisie in A flat); No 2 is the mammoth (over 22 minutes) Introduction, variations and finale, one of the very few works ever written for the right hand alone; and No 3, ‘Mouvement semblable et perpetuel’, is a five-minute rondo-toccata for both hands in unison which, technically at least, makes the finale of Chopin’s B flat minor Sonata seem like a walk in the park. How’s that for starters?

To whichever disc you turn, Alkan continually confounds your expectations or surprises you with the unexpected. Try disc 10 with Une fusée (‘A Rocket’), Op 55, played by Constantino Mastroprimiano on an 1865 Pleyel. Banal? Bonkers? Or a jaw-dropping firework display? Is there another piano work before the late 1850s that features cluster chords? Tracks 7 to 10 contain the extraordinary Sonatine in A minor, Op 61, described by Sorabji as ‘vehement, droll, gargoyle-like, childlike and naive in turn – almost as though Berlioz had written a Beethoven sonata’.

The Sonatine is one of a few duplications of repertoire (though the longest by far) included in this box-set, a strange decision by Brilliant Classics for, though almost all Alkan’s best-known and most important works are here, it is a great pity that the Trois Études de bravoure, Op 12, ‘Fa’, Op 38b No 2 (from the second book of Chants) and Le chemin de fer, Op 27 (the first piece of music to simulate a piece of machinery) are absent. The Sonatine in Vincenzo Maltempo’s performance on a modern instrument (disc 3) aptly follows its predecessor, the equally astonishing Grande sonate, Op 33, otherwise known as ‘Les Quatre Âges’, four movements representing a particular stage in a man’s development, each becoming progressively slower.

Not all the music, performances and recording are on such a high level, a case in point being Giovanni Belucci’s horribly aggressive live recordings from 2013 of the three Scherzi de bravoure, Op 16. Save yourself for the two sets of studies in all the major and minor keys which, in the words of one of Alkan’s foremost champions, Ronald Smith, ‘within their 370 [sic] or so pages is engraved the most complete evidence of what must have been an almost frightening keyboard command’. Mark Viner gives us the finest account ever committed to disc of the 12 major-key studies (Op 35), surpassing the excellent Stephanie McCallum (Tall Poppies, 1992). Viner’s disc, the most recent recording (2016) of the collection, is also issued singly (Piano Classics PCL10127) with the further bonus of the pianist’s own detailed and illuminating booklet (Brilliant’s English-only booklet is as good as far as it goes, which is nowhere near as far as the individual booklets for the original issues of all these discs). The mighty 12 minor-key studies (Op 39), at the centre of which is the mind-boggling Concerto for Solo Piano, are allotted to Maltempo. Like all the greatest recordings of this work (Hamelin, Gibbons, Ogdon, Smith), Maltempo swallows it whole with an intense musicality and technique to spare, though he does not dislodge Hamelin from pole position (Music & Arts, 8/93 or Hyperion, A/07 – two of the greatest piano recordings ever made).

What else? Chamber music (Violin Sonata, Cello Sonata, Piano Trio), Laurent Martin playing the 25 Préludes, Op 31 (in all the major and minor keys) and the 49 little gems that form Esquisses (‘Sketches’), Op 63; and then – to wrong-foot you again – a disc of Alkan’s organ music from the astounding Kevin Bowyer (a Nimbus disc from 1988) ending with the Impromptu on ‘Ein feste Burg’, originally for pedal piano. There’s much more besides. Over 15 hours of music by ‘the most neglected genius of the 19th century’ – and all for the price of a good single malt.