For some reason, the ‘Recording Level’ slider (under the ‘Browse’ tab in the ‘Track Info.’ Pane on the right of the screen) is greyed-out. Stated briefly, I cannot set the the Record Level and Track Volume level in GarageBand independently of one another. I would like some help with a problem in GarageBand that has only recently become relevant to me as a problem (i.e., I was able to get around it / deal with it up to now, so I did not matter to me previously).