At South By Southwest last month, Saturday afternoon at the outdoor Town Lake stage was a mini-Jazz Fest, with performances by BeauSoleil, Buckwheat Zydeco, Dirty Dozen Brass Band, Ivan Neville’s Dumpstaphunk and Allen Toussaint. In the midst of that was the second performance by the New Orleans Social Club — the New Orleans musicians who recorded Sing Me Back Home last October after evacuating for Katrina. The highlights of the album were the highlights of the show — Ivan Neville’s “Fortunate Son” and Cyril Neville’s “This Is My Country” — but Henry Butler’s version of “Somewhere” felt lusher and lovelier, with an ’80s soul/jazz feel, and Monk Boudreaux’s “Chase” was more dubwise live. The emotional high point, though, was John Boutté’s anguished cover of Annie Lennox’s “Why?” As beautiful as it is pained, the performance captures the sad, desperate feeling so many of us are suppressing or drinking away these days. Boutté’s song and the show itself dramatized the remarkable music community Hurricane Katrina threatened — one that’s not safe, yet.