I've got an old MacBook Pro that is about to run out of HD space. My internal drive is 160Gb. At the moment I have an external 2TB drive connected to it at all times. I know that the main space hog is my iTunes folders. Can I safely move them onto the external HD? And then on have anything added to iTunes be stored on the external drive? I currently use the external for TimeMachine too, will this be a problem?