There are theories that apply to more than one of 'improvised music ... dance, drama and pictural improvisation':
excerpts from the above links:
"The main ingredients of improvisation ...
- Presence and projection are the premises of trust and collaboration.
- Improvisers are sponges feeding on their surroundings. Listen.
- The best ... tend to emerge between - rather than within - people.
"The process can become effortless with practice but without listening there is nothing to adjust to. ... Listening gives them a common space in which to play. Without commitment, there is no one to listen to ... Improvisation requires players to engage fully with each other."
"In any ... combinations ... , some aspects or elements will sound more prominent while others will seem to recede. We use the spatial terms foreground, middleground and background to help us differentiate the various elements ... can constantly change and shift. They do not necessarily have to be fixed."
"A pecking order is the stabilised ranking of individuals in a given social group. The agreement save the time and energy [that] would otherwise be spent on conflicts over access to ressources and privilege. ... The notion is relevant to improvisers on many levels: ... As a person ... As a player ... As a character ... As a storyteller"