It’s the details that betray Lewis’s disengagement. He underplays the waltz theme’s jabbing sforzandos, while Var 1’s inconsistently observed rests flatten out the Maestoso march’s gruff character. Also notice Lewis’s sluggish, almost uniformly even and tensionless dispatch of Var 2’s broken chords, in marked contrast to Stephen Kovacevich’s quicker, infinitely more varied approach (Onyx, 1/09). Vars 11 and 12 similarly sound square and uneventful next to Brendel’s enlivening inflections of phrase. True, one cannot quibble with Lewis’s rhythmic poise in Var 5, Var 6’s fiercely uniform trills and marked expressive contrasts, or the comic timing of Var 13’s silences. But I wish he’d allowed just a little more breathing-room between unconnected variations, so that their individual characters can establish themselves.

Lewis’s fast and glib traversal of Var 9 totally misses the meaning behind Beethoven’s pesante e risoluto directive, not to mention the short-changed right-hand szforzando accents. Var 10’s rapid chords are flawlessly tossed off, yet the crescendos lack real ferocity (here Lewis takes the chords on bar 56’s last beat and bar 57’s down-beat up an octave). Although Lewis projects volatile contrasts between Var 21’s Allegro con brio and Meno allegro, he bridges them with unnecessary ritards. And while one can take accurate dictation from Lewis’s scrupulously executed minor-key triumvirate (Vars 29, 30 and 31), don’t expect the stinging accents, urgent slurs and heartfelt melodic trajectory with which Arrau, Schnabel and Brendel grip your attention.

Perhaps the mellow resonance of Harmonia Mundi’s engineering squashes Lewis’s dynamic range down a few notches; but, then again, my favourite recent modern CD Diabellis (Benjamin Frith on ASV, the Stephen Kovacevich remake and Daniel Shapiro’s powerful, gutsy version on Azica) are no sonic paradigms themselves. A gorgeously engineered late-1970s production preserved Charles Rosen’s impeccable tempo relationships and flexible virtuosity in an unambiguously great interpretation that cries out for reissue. Still, there’s no doubting Lewis’s potential to give us a Diabelli Variations of equal stature but this release ultimately promises more than it delivers.