Occasionally, after we’ve smoked ourselves into a kush-coma, we have dreams about the cool kids taking over Second Avenue and showing the tourists what actually happens here in town. Instead of Confederate flag boxer shorts, “Proud to be an American” T-shirts made in China and whatever that infection is you get from licking the bottoms of cowboy boots, the folks from out of town could catch, oh, maybe a really good rap show. Or better yet, a whole street of good rap shows. Tonight’s show at The Attic — a surprisingly cool little bar given that it’s right in the heart of Nashville’s darkness (Second Avenue above Piranhas Bar and Grill) — is about as close to that dream coming true as we’re liable to get. Gray made one of the strongest debuts of 2011, Nitro’s futurist dub-hop is a pure party-starter, and Kaby and Classic Williams have been on every hot bill in the city.