Bach apparently wrote the ‘Air and diverse variations’ for a young house-musician, Johann Gottlieb Goldberg, to play to his sleep-deprived master, Count Keyserlingk.

Despite its length, it is unlikely that the Count would have drifted off. Bach crafted his work for the delight of “the [connoisseur’s] soul”, so constant attention to detail is rewarded.

Before Sarah Grunstein set sail on her Goldberg voyage in the Primrose Potter Salon, she helpfully mapped out the route Bach had charted: the bass-line theme, the variations’ uniform harmonic structure, and some of the many musical landmarks. 

Knowing what to listen for – a lament, a gigue, the overture at the half-way mark, and regularly recurring canons – added enormously to the experience. 

Sarah Grunstein. Photo supplied

In the intimate Primrose Potter Salon, we could see and feel how Grunstein shaped her performance. We were momentarily soothed by a flowing scale passage but then re-energised by a jumpy dance or mentally challenged by a fugue. The baroque ornamentation sparkled on the grand piano, and the hand-crossings – more difficult on a single keyboard than on the two-manual harpsichord Bach had in mind – were executed with theatrical flair. 

Grunstein has made a lifelong study of historically informed performance and has a passion for period instruments. Her program notes outlined the challenges involved in articulating and colouring Bach’s contrapuntal writing. 

Performing the Variations on a grand piano lent weight to the music. In Variation 16 (the ‘overture’) the rich piano tones added majesty; while in Variation 25, the resonance added intensity. 

It was the intensity of the musical experience that set this live event apart. Grunstein performed this long and complex work by memory: a remarkable feat of concentration and stamina. The final, soothing repetition of the original Air made for a satisfying conclusion to a fascinating performance.

Sarah Grunstein performs Bach’s Goldberg Variations in the Utzon Room, Sydney Opera House on 28 October.