A mechanism in an automatic tape cassette changer for engaging and moving tape cassettes from a tape cassette container to engage a tape cassette player/recorder. The mechanism comprising an engagement mechanism on a rail and a cam mechanism, where the engagement mechanism engages one of a plurality of tape cassettes in a tape cassette container and moves the tape cassette engaged along the rail to a second position where the cam mechanism causes the tape cassette engaged to move into a playing/recording position of a tape cassette player/recorder, the engagement mechanism then moves back along the rail to its initial position and remains there during the playing/recording of the tape cassette engaged with the tape cassette player/recorder. The mechanism provides for this series of steps to be performed in reverse when the tape cassette in the cassette tape player/recorder is to be moved back from the tape cassette player/recorder to the tape cassette container.