The Festivus benefit concert is off the hook with absolutely soulful and blistering rock ’n’ roll music this year, with the Detroit Cobras, the Howling Diablos, and the Royal Blackbirds. Many Detroiters look forward to holiday times so that they can unwind from the myriad pressures of the holiday season with at least one local set by the Cobras. They’re so much fun, it’s hard to believe the experience is legal. The Diablos and Blackbirds are nothing to sneeze at, of course — what a show! There’s also a market, drinks, food, and activities for the young ones. The concert is a benefit for South Oakland Shelter to support their programs that provide realistic options for homeless and at-risk.