Live Music

On Monday, we’ll hold a rehearsal with a couple musicians, one with an upright bass and the other with a muted trumpet. This will mark the beginning of a larger project which may be filmed. I’m aware that StoryBox has made great use of the Ambient Sound Machine, but have there been any applications of live music on the form?
Aside from the obvious consideration of volume, we’re already keeping in mind the emotional impact that music can have. We don’t want it to be a major influence on the spect (e.g. manipulating their emotions through tear-jerking chords or a quick tempo), but it will be interesting to try it out as a backdrop.
If you’ve attempted such work before, what insight do you have?

Much appreciated,
Shea