The Portsmouth Sinfonia was an orchestra founded by a group of students at the Portsmouth School of Art in England, in 1970. The Sinfonia was generally open to anyone and ended up drawing players that were either persons without musical training or, if they were musicians, ones that chose to 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.
Bryars was interested more in experimenting with the nature of music than forming a traditional orchestra. Instead of picking the most competent musicians he could find, he encouraged anyone to join, regardless of talent, ability and experience. The only rules were that everyone had to come for rehearsals and that people should try their best to get it right and not intentionally try to play badly. The first recording made by the Sinfonia was a floppy 45rpm disc of Rossini's William Tell Overture, which was sent out as the invitation for the degree show that year.
The early repertoire of the Sinfonia was drawn from standard classical repertoire (such as "The Blue Danube" waltz and "Also sprach Zarathustra"), so that most orchestra members had a rough idea of what the piece, or at least famous parts of it, should sound like, even if they could not play their chosen instrument accurately. In later years, the group's repertoire would expand to popular music, including rock and roll.
Many modern composers and musicians found this to be interesting and even profound; the comedic aspects of the music were merely a bonus, though it was used extensively for marketing purposes. Brian Eno was interested enough to join the orchestra, playing clarinet, and subsequently producing their first two albums.