Uncrowded Portion RF Band?

Hopefully some of you are familiar with the RF band in the United States as dictated by the FCC.

I am looking for a frequency to transmit a low powered (5-10mw) series of audio tones. I don't want the band to be crowded (i.e. FM/AM bands). Was hoping somebody could give me a hand.... any suggestions? Of course, I want this to be legal as well.

I've already looked at the FCC part 15 PDF, and it didn't really answer a lot of my questions.

AFIK there is no answer to your question. There are places where you can use unlicensed voice communications such as the FRS(Family Radio Service) or GMRS(General Mobile Radio Service)

You did not indicate what frequency range you are interested in or how far the signals need to go.