Jon Edgar is a British sculptor of the Frink School. Improvisation is an important part of his reductive working process and developed from the additive working process of Alan Thornhill. Final works are often autobiographical, perhaps referencing anxieties or pre-occupations at the time. His body of work includes many clay portrait sketches of eminent sitters.

Improvisation, often shortened to improv, is the activity of making or doing something not planned beforehand, using whatever can be found. The origin of the word itself is in the Latin "improvisus", which literally means un-foreseen – but it is also related to both the old French word "emprouer" and the English "improve", to improve. Improvisation in the performing arts is a very spontaneous performance without specific or scripted preparation. The skills of improvisation can apply to many different faculties across all artistic, scientific, physical, cognitive, academic, and non-academic disciplines; see Applied improvisation.