CC is short for continuous controller. CCs control various MIDI data. CCs can make a stagnate BiaB MIDI track come to life. Here is a list of CCs:

https://professionalcomposers.com/midi-cc-list/#:~:text=MIDI%20CC%20List%20%E2%80%93%20Most%20Common%20Parameters.%201,%28filter%29%209%2074%20%3D%20Frequency%20Cutoff%20%28filter%29%20

Some CCs are universal; CC7 is volume, CC10 is pan, etc. Some are designated by the software you are using, in other words the software determines what CC numbers it will use to modify its parameters.

The mod wheel is designated as CC1. It can be used for vibrato, expression (CC11), or in Garritan's case volume. This is done so one can play notes or chords with the right hand and control the volume/swells with the left hand.

I hope this helps.

I'm no longer allowed to go caroling at the psych hospital.
I guess Do You Hear What I Hear was a bad song choice!

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware