Portsmouth Sinfonia

The Portsmouth Sinfonia was an orchestra founded by a group of students at the Portsmouth School of Art in Portsmouth, England, in 1970. The Sinfonia had an unusual entrance requirement, in that players had to either be non-musicians, or if a musician, play an instrument that was entirely new to them. Among the founding members was one of their teachers, English composer Gavin Bryars. The orchestra started as a one-off, tongue-in-cheek performance art ensemble but became a cultural phenomenon over the following ten years, with concerts, record albums, a film and a hit single. They last performed publicly in 1979.

http://en.wikipedia.org/wiki/Portsmouth_Sinfonia