The reactable was intended to be a right-brained musical instrument for multi-user electronic music performance. It should be attractive, intuitive, non-intimidating, and suitable for everyone from children to professional musicians who can start playing from the first minute. Creating can be fun, but we did not want to conceive a sound toy.

Whereas many sound installations might be little more than expensive toys that become boring and predictable after a few minutes, we wanted to create something more challenging and complex, like a traditional music instrument, something capable of rewarding effort and time spent to master it.

The reactable has a tangible, visually compelling and intuitive user interface, which makes music visible and almost graspable. The instrument should also support collaboration among various players. It is based on a luminous round table and can be played simultaneously by several performers, who can move, rotate and relate glowing acrylic objects that represent the building blocks of electronic music combined with a tangible, flowcontrolled programming language.

Following its popularity, boosted by YouTube at the beginning of 2007, during the last year the reactable has been shown in 80 locations in 25 countries, in Europe, Asia and America. It has been adopted by professional musicians such as Bj�rk, who has been using the reactable extensively during her current world tour. The reactable has also been acquired by various international art and science museums for permanent exhibitions.

Sergi Jord�, G�nter Geiger, Martin Kaltenbrunner, Marcos Alonso / Music Technology Group, Universitat Pompeu Fabra, Barcelona