Richard Wagner's opera Tristan and Isolde (variously spelled as Tristan and Isolda, Tristan and Yseult, or Tristan and Ysolt) is the Romeo and Juliet of German opera. The mere mention of the names gives the connotation of unhappy lovers in a secret relationship with an unhappy ending. There are many versions of the story available that almost everyone has at least some idea of what is going on which makes it one of the ‘easier’ works by Richard Wagner to watch and actually know what is happening on stage.
When you mention the name of Tannhäuser, people either look blankly at you or assume you refer to the famous opera by Richard Wagner. The opera is correctly called Tannhäuser And The Singers’ Contest on Wartburg, and Tannhäuser is the titular hero in it. Tannhäuser was also a historical knight and singer songwriter.