His voice is smoky and heavy, hers is a fragile soprano. They have each made two solo records. But brother Angus and sister Julia Stone from Sydney, Australia are at their best when they unite their diverse styles. Part of their success is genetic. Pa and Ma Stone were also a musical duo. Their children’s collaboration took place with fits and starts. Julia started with Angus as a guest. Then they operated separately but one sang the second voice for the other. These days they play together but write separately. It’s complicated but the result is fantastic: two top-class talents for the price of one. Their hybrid of folk and indie rock was immediately successful in Australia. Things have been going uphill in Belgium since the single Big Jet Plane (2011). Their latest and fourth album, Snow (2017), resulted in a sold-out Vorst Nationaal last year.