It’s a warm Sydney night in early December 2012, and The Standard in Darlinghurst is packed. The bar is busy, of course, but the punters are here for the show. Ranging from David Bowie to Nirvana, the band’s setlist is eclectic; there’s even some Beethoven and Paganini, too.

Australian Chamber Orchestra, ACO Underground An ACO Underground session from 2012. Photo © Onur Karaozbek

The guest musicians are luminous: former Violent Femmes bassist, Brian Ritchie, is on acoustic bass, and brothers Joseph and James Tawadros on oud and req. Long-rumoured, but finally confirmed at the end of the first set, Radiohead guitarist Jonny Greenwood’s lanky form appears on stage in t-shirt and jeans with his Telecaster and laptop, and plays a dense, complicated excerpt from Steve Reich’s Electric Counterpoint.

The crowd is buzzing, but the mood is relaxed: vocalist and violinist Satu Vänskä converses with the audience between music, relating stories about her time in Japan and Finland. Vänskä is Principal Violin with the Australian Chamber Orchestra, and on stage next to her is the ensemble’s Artistic Director and leader, Richard Tognetti. It’s an ACO Underground gig, a group of predominantly classical musicians who come together...