Kaj Duncan David is a British/Danish composer, performer and sometimes-curator exploring various intersections between instrumental, electronic, audio-visual and installatory forms. His recent work often incorporates light and/or video, sometimes involves concrete/everyday situations, and increasingly explores post-rave aesthetics and scenic or site-specific composition. He often works collaboratively, for example with Danish multi-disciplinary artist Troels Primdahl, London composer collective Bastard Assignments, and Swedish sound-artist Kajsa Magnarsson. Some of his pieces and performances have been presented at festivals such as Rainy Days (Luxembourg), Klangwerkstatt (Berlin), Ultima (Oslo), Spor (Aarhus), NextFest (Edmonton, Canada), LAK festival for Nordic Sound Art (Copenhagen), and at institutions such as ZKM Karlsruhe and Akademie der Künste Berlin.

Groundwave Rondo (Magnetic Travelling) is a collaboration between composer and contrabassist Christopher Williams and sound artist and composer Christina Kubisch. The core of the project is a 20-minute piece for electronics and contrabass, commissioned by Czech Radio's Radioateliér program. Their performance at Spektrum will be a show and tell of the work-in-progress.

The piece brings together Williams' ongoing series of pieces for contrabass and radio signals entitled Groundwave Rondo with Kubisch's research into electromagnetic induction. In Williams' series, each piece is made new on the way to a performance. While on the train, he improvises for 15 minutes with an AM radio and records it. The radio signal is obliterated by interferences from the train motor, overhead cable, and onboard electronics, turning the receiver into a sort of synthesizer which can be modulated by turning the frequency dial. The recording is played back unedited as a duet partner with the contrabass.

In Kubisch's work with electromagnetic induction, which she has carried out since the 1980s, one wears custom-built headphones containing sensor coils that pick up electromagnetic interferences in buildings, city centers, airports or trains and are transformed live into audio signals. These rich and unpredictable sound fields may be heard by participants on planned itineraries (Electrical Walks), or recorded by Kubisch for use in studio composition. She is particularly fascinated by the sound of trains in Eastern Europe, whose different and sometimes antiquated technology produces a radically different sonic experience from modern train systems in Western Europe.

In Groundwave Rondo (Magnetic Travelling), the artists travel by train from Berlin through the Czech Republic to record Intercity and regional trains with both Williams' AM radio and Kubisch's headphones. This recorded sound material will be layered and juxtaposed in the studio to create a new virtual field through which Williams improvises on the contrabass, at times hiding within the electronics, at times playing in counterpoint.

The artists thus address both the audible sound spectrum and normally imperceptible acoustic phenomena rendered audible through special techniques. Here emerge parallel worlds that question what exactly "real sound" is.

Christopher Williams: Groundwave Rondo (York)

https://vimeo.com/86058616

Christina Kubisch: WAVE CATCHER

http://vimeo.com/57325864