How do you sing underwater, let alone play a string instrument? Danish avant-garde ensemble Between Music bring their ethereal underwater concert Aquasonic to Australia for the 2018 Sydney festival. Five musicians, submerged in separate water tanks, will sing and play custom-made subaqueous instruments, such as Nanna Bech’s ‘rotachorda’ – a brass chordophone which pays homage to the hurdy-gurdy.

Sydney festival takes place 6-28 January, with the full program announced on 25 October