The Perimeter = I-285 (loop freeway), since nobody clarified that. ITP = Inside The Perimeter; OTP = Outside The Perimeter. This is the big cultural divide in the Atlanta area, and I think it's an unfortunate and shameful one. We're one big metro family and there's goodness everywhere.
I live right between Lawrenceville and Suwanee, and I like it here. Gwinnett County is MUCH better than people give it credit for being. If you can get to work without even getting onto a highway (I can!), you're way ahead of the game. Housing is less expensive out here, crime is lower than in the hipper ITP areas, there are more trees, easier access to the rural countryside like Lake Lanier and the North GA Mountains (If you dig nature), diverse people (Gwinnett has one of the largest Korean populations in the eastern US, and probably the largest eastern European population in the south, lots of Latins too), relaxed atmosphere, good shopping, and you'll be really close to 85 so you can easily bop on down into the city whenever you like. We've got some nice little music-shops out here who can keep you supplied with strings & such, and there are fancier places to buy gear down in the city. Atlanta has a great arts-scene too, and an amazing plethora of different restaurants. We've also recently surpassed Dallas for being the #2 movie/TV production city in USA.
Music is really diverse here, with something for everyone. The scenes that Atlanta is big in are hip-hop and, believe it or not, instrumental surf. I play in a surf-band. You wanna play jazz, country, metal, bubblegum-pop, Celtic jigs, whatever- you'll find it here. Acts of all styles and sizes come through, playing everything from big arenas to cozy clubs. Plenty of festivals too if you like your music outdoors.