Cornelius Cardew's Treatise Composition rejecting notes and structure.
DEC 3, 2012 – Cornelius Cardew, a left-leaning musical activist who was heavily involved with street fights against fascists that often landed him in jail, was a victim of an unsolved hit-and-run in 1981, and some content that he may have been targeted and assassinated for his heavy politics and activism. Cardew was an English "avant garde" experimental piano composer who also challenged the status quo of piano composing. He even challenged using notes and the rigid structure of sheet music. He created compositions on paper with symbols and geometric shapes instead of notes, with no explicit instruction for the instrumentalist; although he stressed artists should get together beforehand and decide how they would interpret the symbols and shapes. One of his most famous was "Treatise".
Cardew later then rejected his experimentation for what he called, "People's Liberation Music". He joined forces with many other British musical activists, and formed the "Peoples Liberation Music group", and wrote songs such as, "Smash the Social Contract" and got heavily involved with Marxism and communism; he fought against neo-Nazism revival in Europe which many people believe may have made him a target for murder. Read more about him on his Wikipedia page. Tom Service of the Guardian has a blog post up detailing his life and career, his politics and then his sudden death at the young age of 45. Check out a composition from Cardew from back in 1974, called "Revolution is the Main Trend".