I just got my hands on a recording with the “lost” Miles Davis Quintet (with Wayne Shorter (ss, ts), Chick Corea (el-p), Dave Holland (b, el-b), Jack DeJohnette (d)) from the Plugged Nickel in Chicago. I’ve only listened to one track so far (Agitation) but I’m again amazed at the power and level of imagination of this group. The fast tempo and the rolling time on this track, and the instant communication between the members of this group is stunning. And it is impossible to imagine this music created in any other manner then by improvisation. In that sense it is an example of idiomatic improvisation; idiomatic with regard to the art of improvisation.