All but the most valiant or foolhardy would dream of tackling Bach’s Goldberg Variations, Beethoven’s Op.109 and Mozart’s Rondo K511 all on the same programme. Last night’s concert illustrated just how courageous and gifted American pianist Jeremy Denk is. The programme alone would tell you of his seriousness of intent, while the playing was a revelation of the glories of this highly complex music.

There were two things that most impressed me with Denk’s playing: firstly, his pellucid touch that was capable of producing the most ravishing of pianissimos or extraordinarily powerful sforzandi. Secondly, his intelligent and thoughtful reading of each piece gave him an architectural vision of the music so that each phrase was shaped with regard to the whole, a trait that created a veritable cathedral of sound in Bach’s Goldberg Variations.

The Rondo in A minor is a dark piece of music reflecting perhaps the turbulent events of Mozart’s life of this period, namely, his friend’s death and his father’s illness. And though the mood may occasionally lift with more cheerful themes, it cannot fully dispel the sadness which lingers around this piece like a miasma. Full toned and sensitively shaped, Denk caught the poignancy of the opening from the start. As the cloud lifted at times, patches of sunlight stole forth with cheery staccato sections and perfect cadences in the major before these diaphanous sounds dissolved into more soul-searching harmonies. It was poetry in music how Denk allowed the delicate wisp of melody to be gently buoyed by the left hand at the end.

One of the last great piano sonatas, Beethoven’s Sonata no. 30 in E major Op.109 is a remarkable work on many levels. After the titanic length of the previous sonata, the Hammerklavier, this one is almost miniature by comparison (a mere 20 minutes). But within this condensed framework lies an utterly original structure: a short, alternating fast-slow first movement, a blur of a second movement, followed by a theme and six variations which represents the climax of the piece. The elusive nature of the shimmering vivace was well conjured up while the high notes glistened with all the pearly delicacy of filigree of a Chopin nocturne. As the arpeggio swept down the keyboard to C major, there was a huge wave of sound, to be replaced instantly by one of great delicacy.

The prestissimo second movement was attacked with bravura in one of the faster readings of this movement I have come across. The sudden pianissimo echoes were splendidly ephemeral and while it was not an absolutely clean rendition it was utterly worth it for the verve and panache with which Denk polished off this movement. It was with characteristic expressiveness that Denk shaped the opening theme of the Finale while keeping the trajectory of the sonata as a whole ever in mind. The first variation kept this same expressiveness while in the third variation, Denk excelled at highlighting the contrapuntal lines. It was not only this ability to highlight the fugal nature of variation five that impressed or the virtuosic sixth variation with its glorious trills and rapid scales, but the palette of tonal colouring at Denk’s disposal in the slower fourth variation with its delicate pianissimos and warm ff chords. The final restatement of the theme at the end was imbued with great peace and serenity.

Just as the first half ended in tranquillity so did the second half begin. The Aria that opens and closes the Goldberg Variations is simplicity itself, and here Denk allowed the music to sing out simply and poetically, unfurling the delicate threads of melody. Technical challenges abound within the 30 variations, not least because Bach probably wrote them for a harpsichord with two manuals and so there are treacherous crossings of hands when played on a one-keyboard instrument like the piano. But more than this, Bach’s Goldberg Variations are a paean of praise to his creator, a rejoicing in the elementary delight of music and this came through in Denk’s interpretation.

The chattering lines of counterpoint woven seamlessly together in Variation 2 or the wonderfully dexterous crossing over of the lines in Variation 5 formed a perfect backdrop to the gentle caressing of the Sarabande in Variation 13. The latter was an oasis of calm and reflection before the explosive energy of Variation 14 burst forth with its rapid bird-like trills and sparkling finger-work. And while the majority of the variations bubble along with frothy good humour the Variations in G minor (nos. 15 and 21) had a poignancy that Denk brought out but refused to wallow in it. The final five variations grow ever more exuberant dispelling the sorrow of no. 25, before Denk played the still and wondrous Aria that brings this sublime work to a close.