In April 1974, just weeks before the annual New Orleans Jazz & Heritage Festival, Professor Longhair’s house burned — he lost everything he owned but the clothes on his back. So on April 22, the New Orleans Jazz & Heritage Foundation staged a benefit concert for him at the Warehouse, featuring a who’s-who of New Orleans R&B at the time: Allen Toussaint, Dr John, the Meters, the Wild Magnolias, Tommy Ridgely, Earl Turbinton, and others — as well as Professor Longhair himself. The show was recorded on multitrack tapes, as a document of the Foundation’s first-ever philanthropic effort.

Known as the Fire Benefit, the concert became a legend. But the tapes, which are housed at the Archive of the New Orleans Jazz & Heritage Foundation, have only ever been heard by a select few. Until now.

This Wednesday at 1p, WWOZ’s Jazz Fest at 50: Opening the Vaults series continues, with an hour of highlights from the Fire Benefit, selected and produced by WWOZ show host George Ingmire.