Noticed them two days ago , yesterday they where hanging around all day , I have spotted them briefly before , but not here . Looked like a reverse coloured magpie . But the  they started singing ! Wonderful !  They are curious of me too - in a nearby tree watching while I was  weeding the  veggie garden and singing a curious song . I copied it and sent it back to them, but then they elaborated  and developed the theme, they continued developing it all day . Now, early this morning at pre dawn, they have started again with the basic tune  . Very melodious , welcome new visitors .   The Pied Butcher Bird .   [ I have  standard  ( Grey) Butcher Birds , they are always here  and we are well used to each other  - they bring their babies here for food when its scarce and turn up for a feed every time a mower, tractor or chainsaw starts . Very tame , come when called .   Grey Butcher Bird ;       ]   The Wiki article on them explains a bit :   " A tame and inquisitive bird, the pied butcherbird has been known to accept food from humans....    The pied butcherbird has been considered the most accomplished songbird in Australia,[25] its song described as a "magic flute" by one writer, richer and clearer than the Australian magpie.[29] Song melodies vary across the continent and no single song is sung by the whole population. There is no clear demarcation between simple calls and elaborate songs: duets, and even larger choirs, are common.[30] The species improvises extensively in creating new and complex melodies.[31] One of its calls has been likened to the opening bars of Beethoven's Fifth Symphony.[27]   ( This was the basic theme I first heard that they developed  )   "Singing often takes place at dawn, and rarely late in the day. Pied butcherbirds sometimes sing on moonlit nights.[32]   ( This  answers the question we had when we stayed up on the Mountain at Dorrigo for a few months ; 'Why do the magpies here sing all night ? " - they where not magpies but Pied Butcher Birds )   "Three types of song have been described: the day song is the most common, sung by birds alone or in pairs as a chorus or an antiphonal duet, generally over the course of the day and while the birds are in flight. It appears to promote bonding and act as communication.[32] The whisper song is sung more commonly in wet or windy weather, the singer sitting in a tree warbling soft and complex harmonies for up to 45 minutes, often mimicking many other bird species as well as dogs barking, lambs bleating or even people whistling.[33] In the breeding season, pied butcherbirds sing the breeding song at night until dawn, when they switch to the day song. This song is longer and more complex than the day song.[32] In response to threats, pied butcherbirds may chatter or make a harmonic alarm call composed of short, loud descending notes.[33]  "