+1 - You shouldn't be using the MS GS wavetable synth. Its not very good. Use the Edirol VSC or TTS-1 (if your version has that). Those are General MIDI synths meaning they can play up to 16 different sounds at a time and the sounds type follow the General MIDI standard numbering, i.e., 1 is Acoustic Piano, 5 is a Rhodes Piano, etc.