Sure, I think I know what you're driving at. In the following example I have a cloner that has two clones as children. The children are the same except that one produces only one clone and the other produces 20. The parent cloner is set to blend mode. A random effector is then assigned which has "modify clone" set to 100%. That causes the random effector to influence the blend between the two child cloners. Probably clearer if you just check out the file:
3079_vumetermograph.c4d.zip
Of course you can use a sound effector in place of the random effector to make it behave like an actual VU meter.