Step into a certain alleyway in Sydney’s Angel Place and you’ll find a whimsical installation that’s meant to be both seen and heard. Back in 2009, artist Michael Thomas Hill created Forgotten Songs, an installation of 110 empty birdcages suspended high in the air that play the songs of fifty birds that once lived in central Sydney before the colonization and urbanization of the area. The sounds of the calls change from day to night with daytime birds’ songs disappearing with the sun and nocturnal birds, which inhabited the area, sounding late into the evening.