Certain defining aspects were evident from the start: the sudden upsurges and ‘outbursts’ of silence that disrupt the elegant serial writing of Omaggio a Domenico Scarlatti (1967) or the apocalyptic imagery of the First Sonata (1968 – likely inspired by Scriabin’s Fourth Sonata) indicate just where his music was heading. Based in Paris from 1969, Rădulescu evolved a ‘spectral’ thinking based on the natural harmonics of the sound spectrum – one in which the piano, with its tuning predicated on equal temperament, ostensibly had minimal part to play.

Having initially reinvented it as a retuned ‘sound icon’, Rădulescu belatedly returned to the instrument when amalgamating his innovations with the possibilities of the tempered scale. Inspired by the Taoist philosopher Lao Zhu, the next three piano sonatas emerged in relatively quick succession (1991 93). Their formal proportions and musical content may be determined by spectral considerations but listeners can also detect the harmonic explorations of Bartók and Enescu, the textural hallmarks of Ligeti and even the rhythmic intricacies of Nancarrow.

The final two sonatas appeared during the next decade, their idiom enriched by elements of the Romanian folk music that Rădulescu drew on increasingly in his later work. Also present is a modal subtlety that makes the Fifth Sonata (2003) the most poised of the cycle, while the lengthy opening movement of the Sixth Sonata (2007) emerges as a process of variation on a motivic cell that brings Rădulescu’s various philosophical and musical conceptions into a heady and eloquent summation wholly befitting of the composer’s final completed work.

Ortwin Stürmer was crucial in encouraging Rădulescu’s return to the piano, having premiered Sonatas Nos 2 4 as well as the Piano Concerto (1996), which places its composer’s thinking within a more inclusive, even panoramic context. Only the first of these discs is newly recorded but the other two have been remastered to convey the precision and panache of Stürmer’s pianism with impressive clarity. Booklet notes and presentation are exemplary even by Neos’s high standards and this set is cordially recommended as an exemplar for a composer like no other.