Disklavier

Hi to all,

I have a disklavier mark IV, and I've been unable to play back ONLY the L hand of a piano piece.  The song in question is Fur Elise, which was included as one of the sample pianosoft solo songs on the disklavier.

How does one play back ONLY the L hand?  When i choose "Left" only, everything plays.  When i choose "Right" only, nothing comes out.  It would appear that channel 1 contains everything - both L and R hands.  I appears that in order to select one hand over the other for playback would require that the L & R be available on separate individual channels...??   What is it that I'm doing wrong?

thnaks,
ron