I think we wound up with a hundred and sixteen birdcages, different ones sourced from various places, mostly second-hand; we got a lot off eBay and went to second-hand stores and my mother and sister and other people, relatives, were out collecting and picking them up off sides of the roads. So we got a collection of these cages and we then put – in ten of them there are speakers, all-weather speakers, playing back the sounds of bird songs. The bird songs come from files collected by a wildlife recordist and they were all sourced through one of the ornithologists at the Australian Museum, Dr Richard Major, who helped with selecting the species of birds or birdsong that we wanted for the project. We approached him because we wanted to get just those birds that have been forced out of the city by the growth of pavements and buildings and the loss of native habitat, native vegetation. And so he was able to look at existing species around the perimeter of the city and see where they still existed in their native bushland, and when we finally located our site he worked out that it was sandstone-based instead of shale-based and that determines the type of vegetation that grows different food; you know, it’s quite distinct, the sandstone vegetation as opposed to the shale vegetation. And as a result that kind of determines what birds tend to exist on the shale or the sandstone. So the concept is about these birds that don’t – their songs aren’t heard any more in the city. So we wanted to kind of bring the sound into the city and make that an important part of the project.