MAC's suggestion to use CC123 is good practice. This time it didn't help.

With more experimentation, I determined that the problem is that at least one of my files uses a CC72 (decay control). When I load a different seq file, the new file never resets the CC72. Thus the new file uses the old CC72 settings, which causes a long decay. I use a CC121, which is Controller Reset, but this only initializes a selected list of controllers (at least in the VSC), which doesn't include CC72. So now that I know the cause of the problem, I can work around it for now.

As far as sending the SysEx F0 7E 7F 09 01 F7 (GM1 On) as Ian suggested, I have already tried that, as well as SysEx F0 7E 7F 09 02 F7 (GM Off) and SysEx F0 7E 7F 09 03 F7 (GM2 On). I have tried various other messages that the Virtual Sound Canvas should recognize, but nothing works. I have scoured over the help files for the VSC. The Help files indicate which SysEx messages the VSC should receive, but none work. However the Help file does refer to some switches, if they are off, can cause the VSC to not receive SysEx mode messages. I don't see any further explanation in the Help file as to how to make sure the VSC is enabled to receive SyeEx mode messages.

Any further help in getting the VSC to recognize SysEx messages is appreciated.

Lare