I have a Yamaha PSR keyboard, and I'm trying to connect it to my computer's soundcard. The soundcard has a single (one-hole) stereo input jack. What is the proper way to get the stereo output of the keyboard into this soundcard? I notice that the main outs of the keyboard are labeled "R", and "L/L+R", or something to that effect. What exactly does L+R mean? Is that in stereo, or mono? If it's stereo, would a regular "instrument cable" do the job? Or does that take mono only? Thanks in advance.