Symmetry

The second act of Alban Berg’s 1937 opera Lulu includes a three-minute sequence that’s a musical palindrome — after the first 90 seconds, there’s an ascending piano arpeggio, a pause … and then the music unfolds in reverse, a perfect mirror image back to the start.

This music accompanies a silent film that is itself a palindrome in some ways — for example, three people arrest Lulu and put her in prison, and then three liberate her. And Lulu’s husbands in Act I are played by the same singers as her clients in Act III.