"So What" (Miles Davis)

So Miles Davis books time at Columbia's 30th Street Studios for March 2, 1959.  He has a basic idea of what he's looking to record: songs built around basic chords and scales--modes, if you will.  He has a few melody lines sketched out in his head.  But as far as actual "compositions," nothing is written down or meticulously arranged--a direct contrast to his most recent work with arranger Gil Evans.
The musicians (consisting of Bill Evans on piano, Julian "Cannonball" Adderley on alto sax, John Coltrane on tenor sax, Paul Chambers on bass, and Jimmy Cobb on drums) come in for the recording date.  There's little or no rehearsal.  Davis in his badass growl gives them a basic idea of the scales and the changes, and the tape starts rolling.
Evans and Chambers set the tone by playing some scales before Chambers suddenly plays this riff that becomes the foundation of the hook.  Then, Evans follows by playing these accentuating block chords.  After a couple of bars, Davis, Adderley, and Coltrane fall in, playing the two-note pattern: bahhh...baaap...bahhh...baaap...soooo...what
And the rest is serendipity, sheer talent, and a little ESP.