The ZKO has an enthusiastic following, in no small part because there is always a personal welcome and short introduction to the repertoire by one of the players. Equally auspicious: over the weekend before the concert, a referendum for the renovation of the Tonhalle passed with a surprisingly high margin of almost 75%, so spirits were high.

Playing the Fazioli piano whose maker she promotes, Angela Hewitt began with the Keyboard Concerto no. 3 in D major, BWV1054. The first movement’s right hand assumed the string part, the left added flourishes and variations to the bass line. The great vivaciousness in the concerto’s dance rhythms gave the orchestra the chance to swell and recede, while never overtaking the solo line. At one point in her direction, Hewitt shot up her hand like an eager schoolgirl, but also smiled through particularly beautiful passages as if fully aware of the gift she and the players were sharing. Which may have helped define her wardrobe: Hewitt joined the ZKO in a full-length lame gown − one studded top to bottom with gold sequins – and it shone as brightly under the lights as the scintillation of the Bach she and the ZKO would play.

In the second movement, Bach’s dramatic power was amplified; minute hesitations just before a chord gave more air to the notes that followed. In the Adagio, though, set between two more tempered movements, she could have underscored more of the melancholic. Without that dimension, the work carried less of the luminosity we had heard at the beginning, although it clearly had a tendency to “dance.”

When the piece came to an end, Hewitt raised her arms in a gesture of supplication, reminding me of the lithe, sole figure in Ferdinand Hodler’s “Song in the Distance”. As conductor and throughout the programme, Hewitt repeated the gesture at the conclusion of each piece; almost as if with dramatic but humble thanks, I suspect, before her great master, J. S. Bach himself.  

Running some 12 minutes, the Keyboard Concerto no. 5 in F minor, BWV1056 was next, and the shortest of the five works performed. Hewitt’s rapport with the score was entirely comfortable. Integrated into the piano lid, however, the moving blue face of the score on an iPad, while clearly a welcome technology for the pianist/conductor, was somewhat of a distraction. Far more appealing visually were the staccato nods Hewitt used to mark her regular beats, and how, in one dense passage in the third movement, her ear came close to the keys as if to say, “now what do we have here? Overall, though, it was the second movement’s infinitely sweet melody and its counterpoint perfection that made the BWV1056 a highlight.

The third work, Keyboard Concerto no. 7 in G minor, BWV1058, got off to a bad start, but was corrected so quickly that many in the audience weren’t even aware of the bump. Hewitt had cited the first movement as “forthright and determined,” but I thought it threatened to barrel forth with too few nuances, and the dignified Andante was also taken a little too fast for my taste. By contrast, the third movement came to a stunning resolution after dramatic explosives; it was so confident as to verge on having “cheek”. And shared by piano and orchestra, the last single note rang out with the conviction that all of us in the hall were a single body bound by the sheer beauty of this grand musical matrix.

The Concerto for flute, violin and keyboard in A minor, or "Triple Concerto", BWV1044, is perhaps one of Bach’s most frequently played works. In it the orchestra shone; concertmaster Willi Zimmerman’s solo in the first movement was muscular and regal, and Hewitt’s light touch in the first movement was full of optimism. In the second “Siciliano” movement, the complex counterpoint sometimes gave way to dissonant strains that gave Hewitt’s Bach its own intriguing dynamic.

The evening’s final offer, Keyboard Concerto no. 1 in D minor, BWV1052, was performed with terrific integrity and insight. The pianist plays the first movement largely in unison with the orchestra, or trades off the melody with the concertmaster. Notably in the last movement, Hewitt built and dismantled the range of perfect harmonies, staying very close to the keys as if in a kind of personal negotiation. No question that she had extended − and followed through − on an invitation to music as empowered as it was universal. To cite music critic Pamela Margles, Angela Hewitt's Bach remains “… an exploration (not just) of all the things that counterpoint can do, but an exploration of just about everything that music can possibly do – and then some.”