Tetras is an improvising trio formed in 2010 with Jason Kahn (drums, percussion), Jeroen Visser (organ, electronics) and Christian Weber (contrabass). The group is based in Zürich, Switzerland.

Jason Kahn began playing music in the 1980's, initially releasing records on the legendary Los Angeles SST label. During the 1990's he lived in Berlin, playing drums and percussion in many projects of improvised and electronic music. He has lived in Zürich since 2000.

Organ player Jerome Visser has worked as an engineer with The Ex, Tom Cora, The Honkies and many others. He has also played with The Pale Nudes and currently tours in the Trio Kazanchis with Ethiopian singer Mesele Asmamaw.

Christian Weber is involved in numerous jazz and improvised music projects across Europe, having played with a wide spectrum of musicians ranging from John Butcher to Otomo Yoshihide.

(Photo Credit: Juan Carlos Hernandez)