All the trigger warnings.
“Here’s how Peter Sellars describes his [updating of Mozart’s opera Don Giovanni]: ‘There’s a rape and a murder in the first 90 seconds of Don Giovanni … It’s probably the greatest opera ever written. … Don Giovanni is an opera that, 200 years later, we’re still struggling to try to understand.'” (From a 1991 review: read the whole thing, “Peter Sellars’s Streetwise Don Giovanni,” here.)
In fact, even the tamest, most traditional production of Don Giovanni could probably do with a trigger warning.