As is perhaps to be expected in a form which deals in incarnations of fantasy, the discipline of circus itself has undergone many shape-shifting transformations over the past few decades. At the vanguard of these evolutions you will very often find Australian circus company Circa, led by artistic director Yaron Lifschitz. There was 2010’s cabaret-style Wunderkammer, followed by surreal, gender-subversive Beyond in 2013, and more recently Circa’s pared-down, minimalist Humans 2.0, packed with choreography and feeling far closer to dance than acrobatics; albeit dance amped up to eye-popping feats of danger and wonder.

Now the company is pushing the medium even further through a collaboration with Opera Queensland, in a reinvention of Christoph Willibald Gluck’s opera Orpheus & Eurydice, receiving its European premiere at the International Festival. The production, which debuted in Australia in 2019, first came about through a conversation between Lifschitz and Opera Queensland’s artistic director, Patrick Nolan. Lifschitz had long admired Gluck’s work for its classical simplicity and universal themes, and realised it could be the perfect form in which to pair the physicality of circus with the power of vocals.

‘You know Balanchine famously said there are no mother-in-laws in dance,’ Lifschitz says over Zoom. ‘Well in circus there are barely any characters. It’s a very clunky medium for conveying complex historical relationships between people. So I wanted something that had to be narratively simple and yet resonant.’ The production updates Gluck’s straightforward retelling of the Orpheus myth (where the hero descends to the underworld in an attempt to free his wife Eurydice from Hades) to a secure psychiatric unit where Orpheus wakes up unsure whether he has killed Eurydice.

Around this central premise Lifschitz has woven a counterpoint of acrobatic movement, with the circus artists not so much telling the story as echoing and intensifying it. ‘They are moving in and out,’ says Lifschitz. ‘Sometimes they’re architecture, sometimes they’re emotions, sometimes they’re sort of mirroring the characters or amplifying a particular moment. They’re kind of a shape-shifting force through the opera.’ In true ancient-Greek style, they take on various forms. ‘Sometimes they’re dressed as him, they’re dressed as her, they’re dressed as a mixture; and it kind of goes a bit potty, as you would expect, in the end.’

A long-time lover of opera, Lifschitz says  its emotional intensity is the thing that has always appealed to him most, something that pairs well with the physical awe of circus. ‘The end point is a kind of poetic experience you get out of extreme virtuosity, put into the service of powerful emotions and big thoughts.’

The physical realities of circus do however mean there are practicalities to be considered, with upwards of 35 bodies on stage, ten of which are flying and tumbling while others are singing. Were the singers ever afraid of collisions? ‘The singers have all been great,’ says Lifschitz. ‘Choruses can be slightly risk averse. But I have to say, everyone’s super-embraced it. I think once they see how authentic and hard-working the acrobats are, the respect between the musical staff and the singers and the acrobats for each other’s virtuosity, and the difference between those virtuosic forms, always creates a real wave of positivity. Part of what they do is they build this beautiful glowing heart.’

Lifschitz has witnessed first-hand the transformation in some of the musicians’ attitudes. ‘I’ve watched real, hard-baked orchestras that have been very nervous about having an acrobat near them hugging the acrobats as they walk off stage. They really do genuinely seem to bring out the very good side of everyone involved.’

Orpheus & Eurydice, Edinburgh Playhouse, 13, 15 August, 8pm; 16 August, 3pm.