Natalie Dessay and Matthew Polenzani perform “Libiamo” from La Traviata. Acclaimed French soprano Natalie Dessay makes her Met role debut as Violetta, the fallen woman who sacrifices her last chance for love, in Verdi’s La Traviata airing on THIRTEEN’s Great Performances at the Met Sunday, August 26 at 12 p.m. on PBS (check local listings).