Michelle Assay’s harsh yet accurate observations concerning Llŷr Williams’s initial Schubert volumes (2/20) sometimes mirror my mixed responses to the pianist’s third and fourth discs in a projected cycle devoted to this composer’s sonatas. There’s no questioning his technical command over Schubert’s often unwieldy keyboard-writing (the D958 finale’s relentless scales, the D935 No 4 Impromptu’s double notes). Yet Williams’s accomplishments often come up short via comparative listening.

Right at the beginning of the C minor Sonata’s Allegro, I miss the supple shaping and countermelodies others divine from the accompaniment underneath the main theme’s embellished statement (about 33 seconds into the movement). Nor do the extraordinary close-lying cross-rhythmic phrases in the development (starting around 6'11") generate the similar tension that pianists such as Claudio Arrau, Richard Goode and Radu Lupu bring to these passages.

Williams sustains his measured pace for the Adagio well, yet without the soupçon of transparency and flexibility that make Mitsuko Uchida’s slower tempo actually seem faster. And there are crisper, suppler and more emotionally varied renditions of the rollicking finale to be had from Richter and Brendel. Williams’s forthright and highly capable D850 would shine better in a less competitive catalogue, yet, again, one must reckon with Clifford Curzon’s sharper inflection of the Scherzo’s dotted rhythms and the individual profile with which Paul Lewis and Vladimir Ashkenazy circumvent the finale’s potential for triteness.

If anything, the ‘lack of imaginative phrasing and predictable agogic hesitations’ MA cited in her reviews of Vol 1 and 2 become more apparent throughout Williams’s Impromptus. The C minor first of D899 starts out with sober simplicity, yet gets heavier and choppier as it unfolds, in contrast to, say, Maria João Pires’s ravishing cantabiles or Artur Schnabel’s hurling, visionary account. Williams’s scales in the E flat second come off comparatively tinkly next to Krystian Zimerman’s strings of pearls. On the other hand, Williams truly sings out the G flat third, finding a natural balance between the main melody and murmuring accompaniment that justifies the pianist’s slow and decidedly non-alla breve tempo. But his square and sectionalised parsing of D899’s concluding piece holds less interest. The D935 Impromptus have rarely sounded so dry and matter-of-fact, certainly when measured alongside Radu Lupu’s cultivation and sensitivity. Even Rudolf Serkin’s colourless and charmless late-period versions convey more drama and sinew. One hopes that Williams’s poetic capacity as a Schubertian will be more fully and positively realised in future volumes.