I've always found it interesting that when Keith Jarrett played with Miles, he didn't make any of the noises he's famous for. He did it before . . . and after. I guess Miles simply wouldn't stand for it.
I know from seeing him live that he actually can make all these noises while he's playing . . . but I sometimes wonder if on a studio recording he wants to be more precise, and multi-tracks it? I can totally see Jarrett in a vocal booth, whining away to his previously-tracked piano . . . maybe wanting to punch-in some moans that weren't quite right . . .