Suspended above Angel Place, a pedestrian lane that runs between George and Pitt Streets in Sydney, there are scores of cages. In combination with the delicate visuals above, sound artwork rises from below in a wave of calls of long-vanished birds.

“Forgotten Songs” is a collaboration of art and ornithology, to remember the calls of 50 birds that once thrived in Sydney, that have either been pushed to the city fringes or drowned out altogether in the wake of accelerated development.

Originally part of a collection of installations called “Laneways By George! Hidden Networks,” it started as a temporary exhibit, part of an initiative to remind the urbanites of of some neglected sounds and spaces of a more human scale.

The recordings are from species that all once chirped in central Sydney, and they change along with the time of day to match their natural habits. So morning birds sing in the morning, and nocturnal birds call out at night.

The original installation proved so popular, funds were provided by the city to make it permanent, as a lovely, mournful way to remember a long-vanished part of Sydney life.