Insert the a synth from the main menu (Insert > Soft Synth), from the track view context menu (right click in the empty space below the track headers), the + at the top of the synth rack or drag the synth from the browser. Use the Insert Soft Synth Options dialog to select an audio track (if one does not exist for the SC88). After adding the synth, point the MIDI track output drop down to the soft synth. To use the existing SC88 audio track if it exists, skip adding the audio track in the "In