Yes, WilliamG is correct.
I went into the Menu and saw the Now Playing and can now see that the Reader was playing away, but silently (My method only Mutes).
It took me awhile to get it to pause by going into Now Playing and holding down that jog button for several seconds, and it finally seems Paused.
I think this a flaw that Sony needs to address. There ought to be a way to completely turn music OFF.