Should we watch the second act of Tristan und Isolde (without the first or the third)?

There aren’t many operas from which you can extract a single act and make a concert of it, in fact I can’t think of any except ones by Wagner. I’ve been to Act I of Die Walküre, Act III of Die Meistersinger¸ Act III of Parsifal at the Proms, Act II of Lohengrin, and several times to Act II of Tristan und Isolde. It’s not that Wagner’s acts tend to be longer than anyone else’s, they don’t: Handel’s often last as long, so do Rossini’s. It’s rather that some of Wagner’s greatest acts are so rich in musical and dramatic material, so perfectly shaped and have so powerful an impact, quite apart from being extremely demanding of their performers, that it is a luxury to be able to give them all you’ve got and not have to look forward, after an interval of chat and drink, to another draining 80 minutes.