The pre-eminent classical piano music to have emerged over the last half century, Ligeti’s Etudes have received numerous recordings – both in part and as a (still-emerging) whole. If neither of the present releases would be a first recommendation, they offer individual takes on an intriguing synthesis which takes in non-Western and non-classical musics – ‘fusion’ in the most positive sense.

Toros Can is in control of the polyrhythmic velocity of ‘Désordre’, and brings humour to the interlocking rhythms of ‘Touches bloquées’, though the transformation process underlying ‘Automne à Varsovie’ fails to generate requisite dynamic tension. The poetic coda of ‘Fém’ – making explicit the underlying harmonic pattern – emerges rather prosaically; but the dexterity of ‘Der Zauberlehrling’ is impressive, as is the Lisztian toccata of ‘L’escalier du diable’ – though the tendency for the piano to take on a metallic timbre above forte is here at its most pronounced. Can includes the first three of the ‘in progress’ Third Book: the ruminative ‘Blanc en blanc’, the elegant ‘Pour Irina’, and the coruscating figuration of ‘A bout de souffle’ – each securely, if not overly imaginatively delivered.

Idil Biret’s interpretations have altogether greater expressive immediacy, not least in the enfolding rhythmic contours of ‘Cordes à vide’, the ominous momentum sustained in ‘Automne à Varsovie’, and the gamelan evocations of ‘Galamb borong’. A note in the booklet explains her decision to follow – in principal – the score’s musical markings rather than the strict timing indications. Her choice is vindicated by the delicate nuancing she brings to ‘Arc-en-ciel’ or the dynamic shading found in ‘Entrelacs’. The recorded sound, commendably clear if a touch raw in its studio ambience, is well suited to the emotional directness of these performances – placing the music firmly within the context of its Chopin and Debussy antecedents. Leaving aside Book Three, she daringly opts to play ‘Coloana fara sfârsit’ – the player piano original of Etude 14 – and convincingly opens up its rhythmic and metrical subtleties.

For the first 15 Etudes (the remainder will no doubt follow from Teldec), Pierre-Laurent Aimard’s aloof eloquence remains first choice – Biret’s impulsiveness making a worthwhile supplement. Erika Haase’s combative account of Book 1, and Lucille Chung’s incisive Book 2 (Dynamic, A/01) are also highly desirable. But then, this is music whose range of interpretative possibilities is far from exhausted.