ISTM that you're best to look at the guest lists from recent years and figure out which ones book acts like yours. So that way you won't waste time sending a promo of your songs to a dance-only festival (like I have done in the past!)

I also like to get in touch first with a brief "this is who I am and what I do, would you like a promo pack" cos that can save them and you a lot of hassle and postage.

Good luck!