How do you perform songs without a vocalist ? For this co-com- mission, Zeynep Toraman has joined forces with the teams at IRCAM in Paris to develop a synthetic voice – disembodied and uncanny – that interacts with the instrumental ensemble. In response, Gérard Grisey’s Vortex Temporum offers a kind of “desynthesis”, revealing the full richness of instrumental timbre. The performance promises to be all the more striking as it takes place without a conductor.