Another way to phrase the question could be, more generically, is it possible to assign selected midi tracks to one VSTi in one basic move?

I'm auditioning some multipart (15+) midi files from the web. All tracks have channels and GM patches pre-assigned. But none are assigned to a synth. I can assign each midi track to TTS to get a rough idea of whether the file is any good, but seem to have to assign each track one by one. I've a lot of files to audition, so that's a drag.
 
Now, I remember once managing to very quickly get a similar, a mulitpart midi file to play through TTS-1 (appropriate channels and patches) very quickly --it was great, worked almost like a midi jukebox --  but I forgot what I did.  Seems to me it just happened semi-magically somehow, either when when I dragged the file into an existing project with TTS loaded, or when I opened the midi file via the File / open command ... but trying it now, no dice...
 
I've also  tried selecting multiple tracks and right-clicking but didn't see anything like "Assign selected tracks to..."   
 
What's the trick here? Grateful as ever for any advice....
 
 

Select all the midi tracks then move to the midi output drop down of one of the tracks, and I think its shift click on the output of the tts-1, it should select all the remaining tracks to the tts1, each midi track has its own patch change and channel so it will line uop

I don't really know why, but if I right click on a MIDI filevand select Open with Sonar Platinum, it gets imported and automatically assigned to TTS-1 with voices selected.

Thanks guys.  
 
I tried both suggestions. Bizarrely, neither works here, although I've found a solution which is close to Sir Williams' . Right click the midi file in Windows Explorer and choose to open with Sonar. That results in a bunch of midi tracks not assigned to any synth. Then just drag in the TS-1. No need to select the midi tracks. Done -- the tracks are all assigned.
 
 
Never would have guessed that one!
 

You can also select all the tracks you want to assign to the Synth, and then go to Tracks -> Output and assign them all at once.

 

PilotGav
You can also select all the tracks you want to assign to the Synth, and then go to Tracks -> Output and assign them all at once.

Aye, harr, tharr be the best answer! Many thanks matey!  Very useful in this as well as lots of other situations. Damn, thought I'd looked there too ... sometimes I only need to be losing my mind a little bit already to let Sonar convince me it's totally gone ;-)
 
Thanks again. 

Another thing not to do is open or import a midi file inside a blank project. Doing so you lose tempo. Also if you use Microsoft GS Wavetable Synth you do not have to load the TTS just assign the output to the Wavetable Synth.