Coming away from this latest Australian Chamber Orchestra concert I couldn’t help thinking to myself: Is there nothing that Richard Tognetti and this band can’t turn their hands to?

To program Richard Wagner – hardly your usual chamber fare – alongside Gustav Mahler and with the bonus of three songs by his wife Alma Mahler-Werfel is adventurous indeed.

But when you think that Wagner used only 15 musicians placed on a staircase to deliver his best birthday present ever, the Siegfried Idyll, to his wife Cosima, and that Arnold Schoenberg arranged Mahler’s Das Lied von der Erde for similar forces, perhaps Tognetti’s leap of imagination is less surprising.

Australian Chamber Orchestra: Mahler’s Song of the Earth. Photo © Nic Walker

The upshot is that the programme worked splendidly. A string quartet of Tognetti, Satu Vänskä, violist Stefanie Farrands and cellist Timo-Veikko Valve led the way into the Idyll, which was not only a birthday present but also a celebration of the birth of the couple’s son Siegfried.

The ACO comprised a top-notch mix of core musicians and guests from Sydney Symphony and some European orchestras, with the flute of Sally Walker, a regular with Omega Ensemble and ARCO, and SSO Associate Principal Oboe Shefali Pryor both playing prominent parts throughout the evening.

The tour marks the homecoming of two our international stars in helden tenor Stuart Skelton and mezzo soprano Catherine Carby, who gave a rare performance of three of Alma Mahler’s songs, written before any of her three marriages and Mahler’s insistence that she should stop composing.

Australian Chamber Orchestra and Stuart Skelton. Mahler’s Song of the Earth. Photo © Nic Walker

Skelton was far from his best on this opening night concert, suffering from a head cold which left him struggling at times. But even so it was an impressive performance that showed him as a singer who can pin you back in your seat, with the song Von der Jugend (Of Youth) the most successful of his three from The Song of the Earth.

The top notes of the opening catch from Trinklied, a spectacular and challenging entrance at the best of times, faltered, but not disastrously so. Skelton’s experience and artistry won through – you could see him psyching himself up like an elite shot putter about to launch as Timothy Jones’s horn sounded the opening call.

Later the rapid transition from chest to head voices in Der Trunkene im Frühling (The Drunkard in Spring) wobbled and he almost lost his voice altogether in a sotto voce passage. With nine concerts over a fortnight – and with little recovery time in between gigs – this is a gruelling schedule, but hopefully the star Sydney helden tenor will be back on top form soon.

The ambitious ACO tour is also a reunion for Skelton and Carby, both of whom have spent years in Europe and America building their successful careers.

Carby, who started out in Canberra and became a regular with Opera Australia before moving to London and the Covent Garden stage, returned post-COVID for a triumphant appearance in Pinchgut’s spectacular production of Marc-Antoine Charpentier’s Medée.

Australian Chamber Orchestra and Catherine Carby. Mahler’s Song of the Earth. Photo © Nic Walker

She and Skelton have appeared together in several productions, including Opera Australia’s landmark 2009 staging of Benjamin Britten’s Peter Grimes.

Even though their six alternating songs in the Mahler were all solos, there is an obvious warm chemistry between the two.

Carby’s rich and even mezzo, consistent across the whole range and with a mellifluous and potent lower register, was a full of apt mellow fruitfulness for the irresistible Der Einsame im Herbst (The Lonely One in Autumn) and breezy and joyful for Von der Schönheit (Of Beauty).

But, as with so much of Mahler, it is the final moments that leave us transfixed – think of the final failing heartbeat and sigh of the Ninth Symphony, or the transporting close of the Resurrection Symphony – and Carby’s poetic expressiveness was perfect for Abschied (Farewell) and the ecstatic description of the moon “like a silver barque” floating “up the sky’s blue lake”, her voice deliciously wrapped around by Walker’s flute.

Over this magical half-hour setting of Mong-Kao-Jen and Wang-Wei’s poem, Tognetti’s musicians lined up for their lovely solo moments – Valve’s cello, Olli Leppäniemi’s bass clarinet, Pryor’s oboe and Jones’s horn among them – before the final eternal fadeout of “ewig, ewig”.

The diverse orchestration calls for piano, harmonium/celesta and mandolin, and Tognetti kept his varied elements on-point for this deeply satisfying concert. It’s one not to be missed.

Australian Chamber Orchestra performs Mahler’s Song of the Earth at City Recital Hall, Sydney, 15, 17 and 18 May; Queensland Performing Arrs Centre, 20 May;  Melbourne Recital Centre, 22 May; Llewellyn Hall, Canberra, 24 May and Hamer Hall, Melbourne, 26 May. Ticketing and information here.