Here's a pretty good but not quite good enough explanation of the importance of Kind of Blue. There are a couple of inaccuracies.

The author, Fred Kaplan, states that a "scale" consists of the 12 notes in an octave. Well, that would be the chromatic scale--but most music is not based on the chromatic scale but on the seven notes of a major or minor scale. All the "modes" are selections of seven of these twelve notes.

But Kaplan never explains exactly what a "mode" is, so the concept of "modal improvisation" is going to remain vague for someone who doesn't already know this. His contrast between chord changes and modal improv does not really work, because he doesn't quite put his fiinger on the different feeling created by exploring one scale in open-ended fashion for many measures.

He doesn't mention Miles's previous recordings with the Coltrane, Chambers, Philly Joe Jones, Red Garland quintets. Kind of Blue didn't just appear "out of the blue." He doesn't explain what makes MIles Davis's playing so distinctive, or how the contrast between Miles and 'Trane / Cannon is so effective.

He writes as though modal jazz was the first significant development after bebop, ignoring Miles's own invention of "cool" jazz, the innovations of Mingus, Tristano... Hard bop... Even Ornette had already developed his distinctive approach by '59. Seen in its context, KOB is just one postbop innovation among many others. It is not at all true that after the death of Bird people were waiting around to see if there was going to be anything else happening. It already was a happening time for jazz. KOB is just one high note in an extraordinarily rich period stretching from the invention of bop (early 40s) to the death of Trane in 67.

I suppose it's good enough for a non-jazz audience, explaining the contributions of George Russell and Bill Evans. Maybe it will get the few people who don't already know this music to listen. I've seen Kaplan do a lot better, though.