Hi John.

All KORG keyboards have the ability to call up any sound you want from any external module by transmitting MSB/LSB and Program Change data.

You only need to set the track status to external and it will then allow you to send very specific MSB/LSB and Program Change data that have nothing to do with it's own internal sounds.

For example, if you send MSB 10, Program 1 then the SD2 will go to bank C program 001.

Regards
James.