Another Thing I Should Have Known Years Ago

Implementation of CC1 (mod wheel) and CC11 (expression) can vary greatly between instruments.
While it does seem that CC11 does commonly affect volume / velocity levels, I don't think that is a common use for CC1, at least not with the plugins I'm most familiar with.

So, adding CC1 to a track might work well for some instruments, but not necessarily all.
And FWIW, I would definitely recommend upgrading to a MIDI keyboard controller that has mod wheel AND after touch ~
The difference it makes with your plugins and some external synths can be fairly dramatic!

rivers88
Implementation of CC1 (mod wheel) and CC11 (expression) can vary greatly between instruments.
While it does seem that CC11 does commonly affect volume / velocity levels, I don't think that is a common use for CC1, at least not with the plugins I'm most familiar with.

So, adding CC1 to a track might work well for some instruments, but not necessarily all.
And FWIW, I would definitely recommend upgrading to a MIDI keyboard controller that has mod wheel AND after touch ~
The difference it makes with your plugins and some external synths can be fairly dramatic!

Thanks! I agree, I really need to upgrade my midi keyboard. In Aria, CC 1 seems to be the same as CC 7. IO can't find any difference. They both affect the base volume level.

FWIW, I don't know how universal this is but CC#11 is also labeled "expression" and basically lets you ride volume (and sometimes filter or something else) between zero and the actual midi volume (CC#7). Think of it as playing a guitar through a volume pedal and an amp. CC#7 is the amp volume, CC#11 the volume pedal. When you fully open your volume pedal, you get the level you set your amp at, and you can go down to zero by moving the pedal.

Perhaps CC1 is supposed to have this same function in Aria?

Simply put, in the Aria Player Mixer View you will see the following:
Control 7 moves the individual instrument channel sliders for  mixer Volume Control. This is the same as setting the Mixer Volumes.
Control 1 controls the Modulation Wheel. You can see the Mod Wheel at the left end of the keyboard on the Aria Player Mixer screen move as you move your mod wheel up and down.
Control 11 is the same as Control 1 but you can assign control 11 to let's say an expression pedal for operation with your foot. The same as a volume pedal.
Aria is hard-wired to your Mod wheel for controlling volume.
In Sonar I set the midi channel Volume to the loudest mix level I want that instrument at. I then turn on the Automation Lane for that channel and set it up for Control 1 or 11. The automation lane is where I do my actual mix moves for that channel. In other words, The Channel Volume in the midi part is like a Master Volume, set it and forget it. Now when I do my expression adjustments they are done in the Automation Lane.
I learned a long time ago that most DAWs use control 7 for channel volumes and 11 for expression. Working the way I just described will save you some headaches if you move between DAWs to work on the same project.
If you mix using control 7 only, there's going to be a good chance that you'll have to re-mix just about every track!!!
But, if you use control 7 for your channel volume and use control 11 for your mix moves when you import in to another DAW you will PROBABLY only have to change Control 7 because your mix moves are all separate and still there! In would rather have to just turn the track up louder or softer and keep my mix than have to edit the WHOLE track over.
If your a guitar player or do any mixing at all it's easy to look at it this way. Control 7 is the volume on your amp, set it and forget it. Control 11 or for Aria, control 1 is the volume on your instrument that you turn up and down as you play to blend in the mix.
I didn't mean to get long winded about this but it is quite confusing dealing with Garritan and these controller numbers. I hope this helps you to think of it in simpler terms. Good luck!!

ESharpe
You did not state what libraries you are using with the Aria player. 
 
The Garritan libraries  use CC1 as for volume for sustaining instruments; like bowed strings, woodwinds, brass.  Thus you can use CC1 to create crescendos and diminuendos and  to impart expressiveness with variations in volume of both sustained tones and phrases.  Velocity is used for attack the note, so you have have like  a soft (low volume) note with a string attack (just one example).  
 
Velocity is used for volume and tone  for most percussive instruments; like drums, plucked strings, piano, guitar.  
 
The sustain pedal is used to implement legato in sustaining  instruments; like bowed strings, woodwinds, brass. 
 
Looking at the JABB manual it looks like you can use either CC1, CC2 or CC11 for volume/timbre but you should use only one of them.
 
 
note:  cc2 is breath control 
 
 

 
ESharpe: I use the Aria with Garritan (now version 5). On the rare occasions that I do crescendos, I draw them in - somehow; I can't remember at the moment how, exactly. Another reason my music lacks expression. But hey, when you're a Baroque Impressionist, that's what you do. (What is Baroque Impressionism? A term I made up to cover my ass because my music lacks expression).

Aha!