Signs, Games and Messages is the title György Kurtág gave to his collection of miniatures, which contains his Hommage à J.S.B, produced across decades of the now 93-year-old Hungarian composer’s life. It is these ideas, more than intimacy, that thread through this playfully cerebral concert by the Australian Chamber Orchestra: the name Intimate Bach captures the small forces on stage (all performing on gut strings), certainly, but not the escalating intensity, clever humour and rolling momentum of a concert that began with ACO Artistic Director Richard Tognetti performing the Andante from Bach’s Sonata for Solo Violin No 2 in A Minor and reached its climax in a blistering rendition of the sixth Brandenburg Concerto – by way of Kurtág and Brett Dean.

Australian Chamber Orchestra Intimate BachRichard Tognetti, Erin Helyard, Timo-Veikko Valve and Atte Kilpeläinen in the Australian Chamber Orchestra’s Intimate Bach. Photo © Prudence Upton

Tognetti took his Andante at a brisk stroll in the solo Bach, his pulsing accompaniment notes, played on gut strings, barely audible at first under the singing top line, the violinist holding back periodically as if to reflect or take in the passing scenery. He was soon joined by Erin Helyard, whose chamber organ cushioned the more penetrating violin sound as the two players – who have just released an album of Beethoven and Mozart together – interwove their lines in the opening movement of Bach’s Sonata for Violin and Harpsichord in A Major, BWV1015. The piece is a trio sonata, meaning in this case that the keyboard part takes on both the bass (bolstered in the second movement by cellist Timo-Veikko Valve, with Helyard now on harpsichord) and one of the two melody lines. In a feat of dexterity, Helyard highlighted his dual role visually (and timbrally) in the third movement, his right hand tracing melodic lines on chamber organ, exchanging phrases with Tognetti, while his left plucked out a bass line on harpsichord against Valve’s pizzicati. Helyard returned once more to the harpsichord for the celebratory final movement.

The trio were joined by violist Atte Kilpeläinen for a bracket that paired selections from Bach’s Three-Part Inventions, or Sinfonias, for keyboard, with miniatures by Kurtág, opening – after a lilting Sinfonia No 2, BWV788 – with the spare, shifting lines of Kurtág’s Hommage à J.S.B. A single candle on the chamber organ (more atmosphere than light source, given the luminous screens of the musician’s tablets) paled in the flare of a fluorescent light, a vertical, lightsaber-like slash through the centre of the stage, which signified the Kurtág movements. Kurtág’s Ligatura Y, Zank-Kromatisch and Perpetuum Mobile B were spliced with Sinfonias 10, 9, 6 and 11 – the ninth, BWV795, particularly affecting in its anguished reaching, feeding off the taut, compact intensity of the Kurtág. These vignettes led straight into the implacable repeated bass pattern of Marin Marais’ Sonnerie de Sainte-Geneviève – given an exciting, jam-session energy in this performance, with crunching harpsichord, spidering violin and increasingly wild cello – which gave way, finally, to Bach’s wistful Chorale Prelude “Ich ruf zu dir, Herr Jesu Christ”, BWV639.

Brett DeanBrett Dean in the Australian Chamber Orchestra’s Intimate Bach. Photo © Prudence Upton

Brett Dean’s viola burst out of a flurry of pizzicati from the lower strings (cellists Valve, Julian Thompson and Melissa Barnard, and Maxime Bibeau on bass) to open the concert’s second half. Dean wrote his Approach (Prelude to a Canon) on a commission by the Australian Chamber Orchestra and the Swedish Chamber Orchestra, who gave the premiere in Sweden in February last year, as part of the SCO’s Bach Brandenburg Project, pairing the famous concertos with contemporary responses. Dean was one of the viola soloists at the work’s world premiere, going on to perform it at the BBC Proms in London. For this Australian premiere, his sparring partner was Kilpeläinen, the two violists navigating music that swung between feverish activity and almost trance-like quiet – uneasy, sustained dissonances across which Helyard’s harpsichord flickered. The work finally drove forward with heroic energy – and a touch more tonality than in the opening – blazing, attacca, into a robust account of Bach’s Brandenburg Concerto No 6, famous for the absence of violins and prominent viola parts. The second movement was pleasantly contemplative, Dean and Kilpeläinen’s individual timbres showcased in the interleaving lines, before the bustling third saw Valve charging fiendishly with the violas to the finale. There might not have been many players on stage, but this concert was larger than life.

The Australian Chamber Orchestra’s Intimate Bach tours nationally until October 30