Peter Sedgley was born in London in 1930, and studied architecture and building work from 1944 to 1963, when he began painting. His job as an architect was to be part of the rebuilding of post-war Britain, but he resigned in protest against attempts to recreate rather than innovate. He also served as a radar technician in the RAF and was a founding member of a design and construction cooperative.
When Sedgley did turn to art, it was initially to frottage, which he soon abandoned—it lacked the potential for development that he desired. He became interested in colour, reading Goethe and Klee, and befriending Bridget Riley. His friendship with Riley led them to set up SPACE together, with Peter Townsend, in 1968, whilst Sedgley’s investigations led him into the use of shaped canvases and his series of Target paintings. Their soft colours were painted in circles, as Sedgley believes this to be a neutral shape, encouraging the audience to see colour, not shape. He painted these with a soft-edged spray. Up until then, his paintings had been of hard-edged, clear-cut geometrical forms.
 
Sedgley began to project light through his Target paintings in 1967, which encouraged him to innovate, leading him to make video-rotors in the following year. These consisted of endlessly rotating coloured circles, which moved with a mesmerising glow.
In 1970, Sedgley began to pair pure colour with music, producing his ‘Colour Ballet’. This was followed by ‘Sound-Screen’ in 1971, when Carl Heinz Wahren persuaded him to experiment with the two. In this year, he participated in the Artist-in-Berlin programme, moving to the German capital, where he has remained ever since. He continued combining light, shapes, colour, music and movement, and made a sound piece for the Donaueschinger music festival in 1972. In the following year he collaborated with York Höller on ‘Light Ballet’ for the Bordeaux Festival, and, in 1974, in Haus am Waldsee, he worked with the composer Mario Bertoncini, who had invented a type of wind harp. This was placed in a room and played by a performer, light changes dictated by the frequencies of the sounds that they made.