yellow ed mentioned Larkinville, and I'd say that's the best thing going as far as family friendly music in the summer. There are food trucks and everything starts right at 5/5:30 so it's not a late event. And there's beers if you want to have a drink.
Cheap plug: playing there w/Michael Oliver on July 9th.
My son loves the whole area for kids, but he's 3. You could still easily hang out with a 6 month old and have space to walk around, sit down, etc.
in that time i was heavy into Thrash Metal/Rapcore, then i went to Death Metal, then i went to Black Metal/Noise, then i went back to Death Metal, then i went to Nu-Metal/Rap-Metal/Rapcore/Metalcore/Hardcore, then i went to sXe/Hardcore ~DJK