best way to get a grant for documentary.

My girl and I have been talking about making a documentary focusing on the culture of live music. We have long been in the scene and I think the idea of documenting different cultures of people who all share a similar love of music would be most excellent. The question is...How would i go about advertising my idea? I figured today would be the day i took the intiative. This community of mine was the first place i thought of throwing my idea to. This site is the shit so i respect you alls opinion. Pease!

Sorry to break the news but most documentary first timers have to make the documentary themselves then try and self the finished product.