In New Orleans, it's impossible to hear about/think about Austin and SXSW without contrasting SXSW and Jazz Fest. The fact is that they share a few very significant characteristics. Both events represent the one occasion people from around the world have to see certain artists. Many regional artists don't tour, and both events collect most of the heavy hitters.
The more significant similarity is the sense of community that underlies both events. Facebook, Twitter, MySpace and a host of networking events make it possible to build a virtual community, but at SXSW and Jazz Fest, you get the visceral reality of looking around a room at a band that draws 50 or so people in your town and find the space you're in at the festival packed. You can see the numbers of people who share values with you; they don't have to be imagined or assumed. It's very clear that you're not alone.
I've half-joked that Jazz Fest is the high holy holiday for the Church of New Orleans, those whose connection to the city and its culture has taken on the character of belief - something beyond the city and bands' actual ability to deliver. The ideas that are encoded in the city and its music speak to them even when the reality is less convincing. Simply because of its size, SXSW is more than that. It's the gathering for those who believe in rock 'n' roll, its inheritors and fellow travelers. There may be more reflexive irony and cool self-protection in SXSW's adherents, but there's no less of a sense of the meeting of the true believers at it than there is at Jazz Fest.
What the size of both events tells us is that the significance of music in our lives isn't on the wane, just anyone's ability to get paid making it. (Or writing about it, I might add.)