Reactable

The Reactable is an electronic musical instrument with a tabletop tangible user interface that was developed within the Music Technology Group at the Universitat Pompeu Fabra in Barcelona, Spain by Sergi Jordà, Marcos Alonso, Martin Kaltenbrunner and Günter Geiger.

As a tangible is placed on the table, various animated symbols appear, such as waveforms, circles, circular grids, or sweeping lines.

The fiducials are printed black-and-white images, consisting of circles and dots in varying patterns, optimized for use by reacTIVision.

[4] reacTIVision detects cartesian and rotational placement of fiducials on the table surface, then emits the specially designed Open Sound Control based network protocol called TUIO, which communicates to the actual synthesizer and visualization software that outputs to the video projector.

The Reactable has been presented and performed at various festivals and conferences such as Ars Electronica, Sónar, NIME and SIGGRAPH.

[5] Icelandic singer Björk is perhaps the first musician outside of the select presentations and demonstrations to use a Reactable in live performance.

Björk's 2007 world tour supporting her 2007 release Volta used the instrument in several songs including "Declare Independence"; Björk's live inaugural use of the instrument took place at the Coachella Valley Music and Arts Festival on April 27, 2007.

British band Coldplay used a Reactable during their performance of their song "Midnight" during iTunes Festival at SXSW on March 11, 2014.

The Reactable received much attention from bloggers and was featured in major TV shows and popular magazines.