I know I can record ONE main vocal to my Multi-MIDI Track Song, and save it as a .WAV or .MP3 file...However, is there a way to record more vocals on top of that? Maybe by PingPong Recording with the CVP-701 perhaps? I would really like to add harmony vocals to my songs, and was hoping it could be done with the Yamaha CVP-701. Please let me know if this can be done. Thanks!