You need some sort of interface to use as a bridge. I use my Zoom 506II. I plug my bass into the Zoom using a standard instrument cable. On the output side I use a 1/4" stereo to a 1/8" stereo patch cable that gets plugged into the computer's sound card. You do have to have a recording program installed. I use Acid Pro 4. Cakewalk Sonar, ProTools, nTrack, and quite a few other programs will do. Import the groove track into the program and just record your bass on separate tracks.