Thanks for your lovely message. The bird is an immature Grey Butcherbird (Cracticus torquatus) and they are widespread across a large portion of Australia. Along with the other butcherbirds, Grey Butcherbirds have a quite lovely call and you have probably been hearing them without realising it.
You can check more facts about them, plus hear their call, on the Birds in Backyards website (www.birdsinbackyards.net/species/Cracticus-torquatus).
Best regards, Jaynia