This painting is an example of improvised interactive painting using the geometry of Thematic Orchestration.
The term visual jazz came from the concept of a group of paintist improvising together like jazz musicians do in a jazz band.

It was painted in 1992 by five paintists, including 3 members of Extended Vision. Philip Mitchell Graham, Baden C Johnson & Euan Benjamin Graham.

This was a part of a series of Visual Jazz pieces, painted on wedge shaped canvas and assembled together to make a large circle. Which surrounded the Tri-easel.
This a detail shot. The BP is not a square.