Is Tristan und Isolde a jinxed opera? That’s an old question. It goes back to 1865, when the opera was premiered on June 10 in Munich. The first Tristan and Isolde were German tenor Ludwig Schnorr von Carolsfeld and Danish soprano Malvina Schnorr von Carolsfeld, his wife. For their premiere performances the pair were praised by critics and audience alike, not to mention Wagner himself. They sang Tristan three more times, then disaster struck: Ludwig died just 41 days after the premiere and 19 days after his 29th birthday. Apparently the marriage of the first Tristan and Isolde was a true love match: After the death of her husband, the grief-stricken Malvina refused to sing any more.

So began the legend of Tristan as a killer opera. The role of Tristan is notorious for its difficulty, requiring immense stamina and heroic vocal equipment. Ludwig Schnorr von Carolsfeld simply sang himself to death. (Other causes seem more likely — typhoid or meningitis, perhaps — but the idea of Tristan as a killer role is more fun.)

The legend can actually be pushed back a little farther in time. Wagner completed the opera in 1859 and several unsuccessful attempts were made to stage it. Most notably, a Viennese production had to be abandoned after more than 70 rehearsals when tenor Alois Ander simply could not cope with the role of Tristan. Some began to wonder if the opera was simply unperformable. Finally the Schnorr von Carolsfelds proved it could be done.

But not by just anybody. During an intermission interview in last Saturday’s live theater broadcast from the Metropolitan Opera, a member of the Met’s casting staff said that there are just 10 tenors in the world who can sing the part of Tristan at an acceptable international level (she knew exactly where they all were at that moment, she said). A few more can get through the part, she acknowledged, but will never sing at a major house. She named no names.

The Met’s current run of Tristan und Isoldes, which will end on Friday night, has done nothing to refute the idea that Tristan is a jinxed opera. There were to have been six performances starring Ben Heppner and Deborah Voigt, two leading exponents of their roles. But Heppner had to drop out of the first four performances because of illness, leading to a parade of Tristans: John Mac Master (first performance), Gary Lehman (second and third), Robert Dean Smith (fourth) and Heppner himself (fifth). As for Isolde, Voigt became ill and had to pull out in the middle of the second performance, with Janice Baird stepping in, and missed the fifth performance entirely, with Baird once again substituting. That’s not all: In the third performance Lehman was injured when he slid into the prompter’s box (not his fault; there was an equipment malfunction).

Fingers are crossed about Friday’s performance, when Heppner and Voigt may finally be onstage together.

Tristan und Isolde may be jinxed, but it provided what many (including me) believe to be the apex of the Dallas Opera’s 52-year history. In 1975 Jon Vickers and Roberta Knie gave three electrifying performances in the Music Hall at Fair Park that included inspired playing by the Dallas Symphony Orchestra under Franz-Paul Decker. Vickers was one of history’s great Tristans. Though Knie’s career faded too soon, in Dallas her singing and acting were glorious. One of the performances became a part of operatic lore when Vickers, lying onstage as the dying Tristan, suddenly shouted to the audience, “Shut up with your damn coughing!” That has become known as the “Dristan Tristan.”