By groups do you mean you had to create different cagegories to adjust the volumes? I think you can solve the problem by using RPCs and Variables.
1. Add all the sounds for your background music to the "Music" category, which ensure that the tracks get muted for the dash playback correctly.
2. Create a new variable (I think either Global or a Cue Instance variable should work).
3. Create an RPC Preset which will open the RPC editor.
4. In the RPC editor add some curves that control the volume for your tracks for the specific variable values.
This should allow you to control the volumes by setting the variable value based on the game state. You may have to tweak the curves or have multiple curves per track etc. But I think this approach should basically work.
Ashu Tatake
XNA Framework Developer