What if all the world’s a stage? And all the people merely players? So, roughly, go the opening lines of the speech made by the character Jaques in William Shakespeare’s As You Like It. A world with ‘entrances and exits’, in which we play ‘many parts’ through- out our time. Shakespeare’s words are possibly the best-known formulation of theatrum mundi, a metaphor that has resonated throughout European literature and philosophy. A metaphor in which the theatre stands for the world itself, one used to describe its inhabitants as puppets on strings, to portray the visible realm as a poor set of shadows of ideal ‘platonic’ forms, or to disparage the charade of human drama as a tawdry perfor- mance of a godly script. Religious moralising and metaphysical spec- ulation aside, how could theatrum mundi help us now to think about the world, and particularly the urban world – the environ- ments we build in order to make and share in the constructed realities we call human culture? How could the stage – as both a metaphor and also as a set of artforms – help city-makers build environments that enrich our shared realities? But this in turn raises a question: can performance shape the stage itself? How might these crafts work back on the infrastructures that support them?

Digging more into the metaphor itself could give some clues. What happens on stage? Bodies enact movement and sound according to designs encoded in scripts and scores; instruments, objects and scenographies help to augment these movements and sounds, or their meanings; sometimes technologies, lighting and digital media transform the ways an audience sees or hears what is happening. Together, these are the crafts of staging choreography, composition, sound and lighting design, scenography, writing, per- forming. What does it mean to be ‘staged’? It could suggest something is intentional, but also that it is artificial or inauthentic, something that says ‘this is how it could be’ rather than something that simply ‘is’. But these descriptions also sound like the built environment – a configuration of objects and spaces that, through the power structures and social ideas they encode, shape the ways we move, appear to one another, communicate, the roles we can play. Uneven geographies of transport infrastructure are like scores that choreograph move- ment and encounter, whilst the stereotyped images of modernist social housing versus baroque palaces and faux Tudor mansions form scenographies against which social positions are imagined. So, on the stage, ideas of what bodies, characters, social archetypes and reality itself are, or could be, are communicated through an interplay of reality-making crafts. Ideas made public through their encounter with an audience, in place, or watching and listening via technology, and become part of the shared public sphere of ideas about what can be. This is the core of the theatrum mundi metaphor – the blurring between the stage as a space to interrogate society, and society conversely as something staged.

But I think we can and must now push the metaphor further. What is the stage on which these ideas, and the public sphere they form, are played out? Whether taking the form of a television or film screen, a radio, or the boards of a theatre, a stage is an infrastructure for attention. Whoever is occupying it is conferred the ability to communicate publicly to whomever is watching. They who are on stage can be the public. Staging, then, is also infrastructure-making – building the technological or spatial surrounds that frame or raise up a ‘platform’ on which to reach the public. But the platform itself is not enough. The stage is an infrastructure that has other infrastructures behind it. Returning to our metaphor, we can firstly think about the theatre as an institution. Communication, administration, fundraising, outreach, maintenance and care work: these are the forms of labour that are not visible on the stage but build and sustain its ability to gather audiences around it. The stage itself is the end result of these processes and the people, the human infrastructures, who ‘stage’ the stage. Then, we can think about the backstage: the rehearsal rooms and green rooms where narratives are imagined and tested, where costumes are fitted, where scenographies are designed and built before they become public. But also, the physical infrastructures of rigging and equipment, and the people whose craft is to operate it.

So Theatrum Mundi, as a way of thinking about cities, points to an expanded set of crafts with which to analyse and intervene in a shared public realm. But deepening the metaphor, theatrum mundi also offers a way of thinking infrastructurally about the public. It draws attention to the layers of infrastructure, labour and hidden acts of care and creativity that sustain a vibrant shared public sphere, as well as the physical systems and spaces in which that labour takes place. The final question, then, is how the crafts of the stage can help to reveal and intervene in the infrastructures that underpin them. In the context of architecture: can choreography, script-writing and music production, for example, go beyond things that happen after the fact of building, and become tools for working back on the material, economic, and political conditions of urban life itself? Rather than answer this question here, I will leave the projects documented in this edition to propose their own responses. But I will return to the theatre once more for a clue. It is performance-making that has, over time, changed the shape of the stage and its container. It is experimental artists –  in music, dance, theatre and performance art alike – that have wanted to break down barriers between performer and audience, turning the stage inside out or abolishing it completely. It is those artists that pushed performance into new spaces, post-industrial ones for example, changing our view of what a stage can be, and the cultural geography of cities, for better or for worse. These artistic experiments can drive, and must be supported by, transformations in the infrastructures of the stage: new kinds of theatre architecture or indeed anti-architecture; new kinds of art institution, and de-institutionalisation; innovative collabo- ration between artists and technicians to find new ways to bring visions to life. Could new forms of architectural practice – that conceive of movement, sound and narrative as part of their primary material – similarly transform the spaces in which city-making happens, and the spaces it can imagine?