What problem were Miles and his produce Teo Macero trying to solve by their methods of constructing music in the studio in the late 60s and 70s?[1] What was the point of Teo turning the tape machines on while Miles and his colleagues played in the studio and then constructing long pieces of music from different parts of these tapes?
One answer, I think, is this: Miles and Teo was trying to develop a new solution to the problem of combining three elements in jazz: collective improvisation, the density of a large band, and what I will call a long form of music.
[1] This is the first of two papers on Miles electric music. It originated in an email to the fabled Miles list in 1998. Eric Siegel, Patrick Brown, Steve Asseta, and the late Walter Oller, made very helpful comments on it at the time which has influenced this new and improved version. The second paper, Miles on the Post-modern Corner puts On The Corner and Miles subsequent before his retirement in a different context, as an example of post-modernism in music. That paper shows some important differences between the approach Miles takes in In A Silent Way and Bitches Brew and the music of On The Corner and subsequent work.