I'm watching two adaptations of Romeo and Juliet that take two different approaches to the play: Baz Luhrmann's 1996 film Romeo + Juliet and Zeffirelli's 1968 film Romeo and Juliet. There are some obvious differences between the two: one is set in 14th-century Italy, and the other is set in the modern day. But there are some subtler differences between the two adaptations. In particular, I'm thinking of the very different approaches the two films take towards the fight scene between Mercutio and Tybalt, and Tybalt's death.
In the 1968 version, the fight is treated as some sort of extended joke. Mercutio and Tybalt do all sorts of comedic routines with their swords, all the characters are laughing (including Mercutio, Tybalt, and the extras), and it appears to be an accident that Tybalt kills Mercutio, judging by Tybalt's shocked expression. Meanwhile, in the 1996 version, the characters appear to be very angry. They're clearly trying to kill each other, and the ominous music adds to this feeling.
What justifies the differences in approaches here? Which portrayal goes better with what we know about the characters and the themes of the play?