I meant to add to my last post that what makes the good players good is the range of subtle variations to the melody and the rhythm that they bring to the tune. It is very easy for these subtleties to be overwhelmed and obscured by inappropriate accompaniment, chordal or melodic. You really only hear these players at their best on their own or with one accompanist who really knows his stuff. To try and recreate those conditions in a session is at best wishful thinking