The international Fluxus movement encouraged the collision of many art forms. Composers began to construct performance pieces with text and action. Graphical notations engaged the element of chance and the unpredictability of real life. The broad range of styles included abstract images, text instructions, cartoon drawings, alphanumeric, and three-dimensional objects. 

From Plus Minus by K. Stockhausen
Karlheinz Stockhausen, No. 14 Plus Minus detail.

Index of Scores Between 1950 and 1970