 In 1999 he joined Dr Xavier Serra who was establishing the Music Technology Group at the Universitat Pompeu Fabra in Barcelona.Sergi Jordà's doctorate dissertation "Digital Lutherie" (Jordà, 2005) at UPF-MTG set the foundations for new kinds of musical computers for performance and improvisation, based on visual feedback and spatial multiplexion.Between 2003 and 2006, together with Günter Geiger, Martin Kaltenbrunner and Marcos Alonso, Sergi Jordà developed the Reactable