In 2014, Pierre Audi signed a new production of Tosca. Together with set designer Christof Hetzer, he imagined a set with the shadow of a cross hovering above it, thus making the political and dramatic implications of the libretto tangible.

Alexandre Gaillard, head of the Set Design Department at the Paris Opera, reveals the genesis of the production's set, which proved to be an adventure worthy of the work.  

Alexandre Gaillard is Assistant Head of scenery workshops and Technical Supervisor.

I arrived at the Paris Opera in 2003 in the post of assistant to the supervisor of the scenery design department. In 2007, the head of the scenery workshops asked me to oversee all the technical side, a post I’ve occupied ever since. In this job, I follow the entire process of creating the sets: firstly the initial designs with our artists, then, when the plans are ready, I supervise the construction in collaboration with the heads of the different workshops concerned. 

My mission is to guarantee that every set fully answers the requirements of the stage directors and scenographers, whilst taking our own constraints into account. This also means sometimes modifying the choices made by scenographers or working with them to reach a compromise.

The set for Tosca underwent several adjustments between the initial presentation of the drawings and its final realisation at the time of its creation in 2014. When the drawings were submitted, the design consisted of just a single cross: in Act I it was on the stage. 

To show us its position in Act II, Christof Hetzer took hold of it, put two strings round it and there it was suspended above his set. To the problems of a cross on the stage were therefore added the difficulty of suspending it. For us, these problems required completely different technical solutions prompting us straightaway to envisage two different crosses. However, the illusion that the cross is the same before and after the interval remains intact for the audience.   

The hanging cross is the one that required most thought. First of all, we reconsidered its shape and dimensions with the scenographer. It required three motors to suspend it and it had to be mobile which provided an additional challenge.

We had to consider how to construct a metallic skeleton for the cross as well as the best way of covering it, that is to say, its exterior panels and their decoration. We had to recalculate the dimensions three times before we found the best structural solution: a framework in aluminium tubing reinforced at strategic points with steel elements.

Next, we had to find the best solution for the exterior: it was made mostly out of a composite of polystyrene, carbon fibre and resin which allowed for very rigid but also very light panels.

The Scenery Workshop had one last challenge to face: making the material as light as possible. When the first samples were shown to the scenographer, the decorative layer weighed 1.5kg per m². After a series of tests, the decorators managed to reduce the weight by half and still produce the same visual effect.

Our combined efforts resulted in an overall weight of 2.7 tons and a maximum of 960kg at the leverage points (the limit was 1 ton per motor). Rarely had a set demanded such an investment on the part of the technical and artistic workshops and the Design Department.

The first time we suspended the cross in the workshop it looked so intimidating that we hardly dared walk underneath it. It’s a marvellous piece of opera scenery in that it is full of paradoxes: it’s a highly monolithic object, the rock-like appearance of its outer covering reinforces the impression of density and contributes to the oppressive quality of its presence on stage, although in fact it was made as light as possible and is largely hollow, composed of emptiness.

I was trained as an engineer and have a diploma from the Arts & Métiers school. For me, working at the opera really is “engineering” in the fullest sense of the term. Over and above technical realism, it requires creativity, ingenuity and perseverance to go the extra mile and come up with the bright ideas that will allow you to bring the artist’s vision to life on stage.   

Interview by Milena Mc Closkey

Anja Harteros embodies Puccini’s heroine Tosca. It’s definitely an event: the German soprano is one of the greatest artists of her generation. Every time she makes an appearance - she mesmerizes the public. In 2016, the photographer Elisa Haberer captured her during a rehearsal with Marcelo Álvarez (Mario Cavaradossi).