By Andrew Poretz***The third and final night of the 2024 New York Cabaret Convention, Everything Old Is New Again: Classic Songs, Old and New, was hosted by KT Sullivan, who arrived onstage in a resplendent red gown and wearing one of her signature fascinators. She related that she first wore the gown at her wedding to her late husband, Steve Downey, all those years ago, and it still fit perfe.