Rosenau picked up the electric guitar as a teenager. His only formal training consisted of two weeks of private lessons, at which point he simply began to play along with records by Led Zeppelin, the Cult, and Metallica and dived into the world of high-school rock bands. He went through everything between alternative rock and heavy metal, adding influences from folk guitarists like Harry Chapin, speed metalists Slayer, dreamy alt-rockers Gastr del Sol, and free improv legend Derek Bailey along the way. Music has not been his primary focus though, and he studied in pure sciences. Molecular biologist by day, he has been involved in an increasing number of projects by night. Telecognac and Pele started first, both around 1997. Then came Vermont, whose first album Living Together came out in 1999. All the while, Rosenau learned the tricks of the trade in engineering recording sessions and built a good reputation (he worked on Paris, Texas' eponymous album, among others).
In 1999, Mueller formed the label Crouton, and since then Rosenau has appeared on many of its releases, exploring more experimental paths on guitar (electric or acoustic) and electronics. In Raccoons, with Mueller and instrument builder Hal Rammel, he plays abstract free improv. His first solo work in that direction was released as part of the 3x3" CD set Folktales, Vol. 1 in 2001. The same year came out a collaboration with Mueller and sound artist Aranos. ~ François Couture, Rovi