Hi, I'm new to Sonar. I'm opening MIDI files with a bunch of tracks. What I'd like to do is select VSTs for some of the tracks instead of using the standard MIDI instruments. I must be missing something simple, but I can't seem to figure out how to do it easily. The only way I'm able to is creating a new instrument track and then moving the notes over from the MIDI track, but it seems a bit cumbersome. Is there a better way to do it? Thanks very much.

are these separate MIDI tracks or are the instruments all in ONE MIDI track?
 
if they are separate MIDI tracks, then just insert a softsynth, not using INSTRUMENT Track, and not using MIDI source track (deselect those options in the popup window)
then just set the OUTPUT of your MIDI track to the new softsynth, and set the patch, channel and bank information as appropriate to the softsynth you're using.
 
 
If you're using a MIDI track with all of the instruments in one MIDI track then it's more complicated.  you could try using a CAL script to separate them first and then just follow the steps above.

In X3 the easiest way to assign a synth when opening a MIDI file is make sure there are no MIDI outputs selected in preferences. When no MIDI outputs are selected in preferences, upon opening a MIDI file X3 will automatically assign TTS-1 to the MIDI tracks.