Jazz is harder to understand now than it was back in the 40s and 50s because the repertoire is based around songs that were popular then but are esoteric now. Miles’ repertoire in the fifties and early sixties would have mostly been as familiar to his audience as “Prince.” Listeners would have been able to mentally sing along to just about everything, making all of Miles’ intellectual abstractions easier to parse. Jazz was still commercial music then, and when jazz musicians wrote their own tunes, they had a tendency to be as melodic and catchy as showtunes and standards — Miles’ own compositions of the period, like “So What” and “All Blues,” are about as catchy and hooky as music gets.
If you want to listen to jazz now, you’re at a big disadvantage. Without knowing all those pop standards and showtunes, the improvisation based on them will just sound like random strings of notes. I had a much easier time getting into jazz through tunes like “So What” than through adaptations of standards. Contemporary musicians are playing abstractions of references to abstractions to references to tunes that were popular seventy years ago. It’s left to the listener to supply a ton of historical context. The best way to approach the music is to start on familiar territory with a tune you know and like, and check out how different artists approach it. Miles and Coltrane are great people to investigate, because they liked playing corny pop songs that are still in wide circulation, and because nearly everything they did was so awesome.
[This was an interesting explanation, and not a bad one either. It seems to miss the essence for me though. It’s about the technique of playing standards which is not all of jazz, and barely mentions in passing the communication, composition, and discussion that is jazz. I’m not sure if an explanation like this does a disservice when it fails to scope the discussion. Where does “free jazz” or harmolodics or “Sheets of Sound” Coltrane fit? Sticking to Miles for a second, where does Bitches Brew fit into this explanation? Never mind that an example like Miles’ recording of Time after Time might have provided a somewhat more contemporary example.]