The Christmas concert at Canberra Mini-trains started at 4pm, with a summer heat wave simmering on the former sheep pastures on the south-east edge of the city. The platform, covered in green carpet, was separated from the browning grass and hoof-compacted clay soil of the audience area by a rope with red pendants limp in the still air. On stage, performers in black-tie suits played swing-era arrangements of Christmas carols. A lone raven watched from a fence post. The amplified strains of ‘God Rest Ye Merry Gentlemen’ rolled out over the pastures as the carriages of the mini-trains trundled around the track, a few children and their adults on board.

Standing on stage among performers such as musicians, singers, actors, dancers and perhaps politicians fronting an audience is part of what Erving Goffman calls the ‘platform format’. The scene and configuration of this platform, and so many others like it, presents something different to the coastlines, rocks, geometry and churches. As the platform diagrams for the Sydney Opera House drawn by Jörn Utzon in his Platforms and Plateaus: Ideas of a Danish Architect show (Utzon 1962), platforms stage every level of height. Utzon's ground-plan for the support-substrate of the opera stage is full of steps and stages on a range of scales. The main stages or performance platforms are big steps arranged in front of steps for seating, surrounded by steps for approaching, and standing on wide flat steps. Some platforms do not use elevation for visibility, but sit at the base of a depression. Not all platforms are spaces of performance, but nearly all rely on stages.