The band was founded in 1998 as a duo performing improvised music. In a year, they became a quartet and would perform in the same lineup with occasional guests until 2008. B4’s musical output ranged from ambient, urban ethno, dub and post-rock to trip hop and jazz.

After B4, 2008 became something like a power quartet that delivers a wild mix of krautrock, noise and psychedelic. Everything is thickly wrapped into space effects and electronic buzz. Polyrhythm and disharmony are the spices they love. The  music of the project may range from the meditative minimalism to a noise attack. B4 are very popular with the alternative branch of Czech music reviewers.