They also learned many songs from their father's cover band "Backbeat" during band rehearsals in the family's garage.
Angus and Julia began to collaborate on their musical endeavours in early 2006. Prior to that, both performed as solo artists. In terms of composing material, they write on their own, then work together on structure and harmonies.
Most impressive, though, are the songs – simple but blindingly effective acoustic compositions, warm boy-girl harmonies and delicate, less-is-more arrangements. Resistance is surely futile.
Source: Wiki on Angus & Julia